Labflow Final Review
This is the process of separating a liquid from a solid (sediment) by gently pouring the liquid from the solid so as not to disturb the solid.
Decantation
A sample of air has 5.55 moles of N2 and 1.74 moles of O2. What is the total volume for the sample of air described, if the pressure is 10.15 atm and the temperature is 325 K?
19.2 L
Determine how many significant figures are in the following number. 4500
2
What is the weight per volume of 50.0 mL NaCl solution that contains 3.73 g NaCl?
7.46 %
The separation of the components of a mixture is based upon the fact that each component has different properties
physical
Write the chemical name for: NaNO3
sodium nitrate
Why can't sodium (Na) and iron (Fe) form an ionic compound?
Sodium and iron both form cations.
gas
Takes the shape of its container Can change volume Low density
Hydrogen bonds are extremely important in biological molecules. One example of a biological/biochemical molecule that uses hydrogen bonding is DNA.
The hydrogen bonds in this molecule occur as H from one region bond with O or N from another.
Pouring an approximate volume of liquid into a buret
beaker
Write the chemical name for: Cu2O
copper(I)oxide
A liquid is carefully poured out, leaving the solid behind in the container.
decantation
Colligative properties are dependent on the amount of a solute, but are not
dependent on the nature of the solute.
A reaction is complete when stoichiometrically
equivalent amounts of the reacting substances are combined.
The pressure and volume are increased. What will happen to the temperature?
increase
The relationship between pressure and volume of a gas is inverse so that as volume decreases, pressure
increases
Solution that involves no net movement of water with the cell
isotonic
The calculated amount of product under ideal conditions
theoretical yield
In the neutralization reaction H2SO4+2KOH−⇀↽−2H2O+K2SO4HX2SOX4+2KOH↽−−⇀2HX2O+KX2SOX4 If there is 909 mL of 0.210 M H2SO4 reacting with 427 mL of a KOH solution with unknown concentration, what is the concentration of KOH?
.894
Identify the set of coefficients that balances the equation___PbCl2 + ___K2CO3 → ___PbCO3 + ___ KCl
1,1,1,2
Use the ideal gas law to solve for the temperature of a gas that's kept at 1.62 atm, 22.4 liters, and contains 1.60 moles. Report the temperature in K.
275 K
Convert the following (to the appropriate number of significant figures): 130 pounds to kilograms
59 kg
How can a solid dissolved in water be separated from the water?
Evaporation
Write the chemical formula for iron (III) sulfide.
Fe2S3
For the following forward chemical equation, identify the acid/base/conjugate acid/conjugate base. HCO3−+H2O−⇀↽−H3O++CO32−HCOX3X−+HX2O↽−−⇀HX3OX++COX3X2−
HCO3-A CO32-CB H30=CA H20-B
When completing the ionization equation of perchloric acid with water, fill in the coefficients and products.
HClO4+H2O⟶ 1ClO4-+1H3O+
Design a Lewis structure for PF3 that satisfies the octet rule for every atom. Which of the following correctly describes what surrounds the phosphorus atom?
Three single bonds and one pair of electrons
For the following concentrations, determine if the solutions are acidic, basic, or neutral and select the best answer from the subsequent choices. a. [H3O+]=0.0115 M b. [OH-]=0.45 M c. [H3O+]=1.25 x 10-10 M
a=acidic; b=basic; c=basic
Classify the following chemical reaction as a combination, decomposition, single-replacement, double-replacement, or combustion reaction: 2NaHCO3 → Na2CO3 + CO2 + H2O
decomposition
Determine the ion that would satisfy the octet rule for fluorine.
f^1-
Solution with greater solute concentration than the solution in the cell
hypertonic
Mixtures are separable into these components by
physical means
What is the total number of valence electrons in the compound: C2H6O
20
Convert 108 Celsius to Fahrenheit.
226.4
Identify the total number of valence electrons in SO32-.
26
How many moles are in 43.0 grams of carbon?
3.58 mol
Use the ideal gas law to solve for the pressure (in atm) that is present in 5.6 moles of gas, at a temperature of 285 Kelvin and a volume of 20.0 liters.
6.6 atm
Convert the following (to the appropriate number of significant figures): 40.75 miles to kilometers
65.58
Each answer below describes the connectivity around a single atom. Which answer violates the octet rule (i.e., which one is not a possible bonding configuration for the central atom)?
One single bond and two double bonds
When a sample is described using the units mole, what is being measured?
The number of molecules in the sample
An _________________ chemical reaction is a chemical reaction in which heat energy is needed for the reaction to occur.
endothermic
Most of the matter people encounter in everyday life consists of
mixtures of different substances
Classify the following chemical reaction as a combination, decomposition, single-replacement, double-replacement, or combustion reaction: Mg + 2HCl → MgCl2 + H2
single replacement
Identify the set of coefficients that balances the equation___CO + ___H2 → ___CH3OH
1,2,1
Identify the set of coefficients that balances the equation___HI → ___H2 + ___I2
2,1,1
Identify the set of coefficients that balances the equation___SO2 + ___O2 → ___SO3
2,1,2
Identify the set of coefficients that balances the equation___ICl5 → ___Cl2 + ___I2
2,5,1
What is the pH of a solution of 1.00 L of water with 0.0384 moles of NaOH in it?
12.6
How do conversion factors affect the number of significant figures in a problem?
Many conversion factors are available to a large number of significant figures or, in the case of exact numbers, infinite significant figures. The number of significant figures the answer is almost always limited by the number of significant figures in the starting values.
Predict the ionic compound that would form when each of these two ions come together: Na and F
NaF
What is necessary for a molecule to be considered polar?
Polar molecules have a net difference in electronegativity over the entire molecule.
Convert the following (to the appropriate number of significant figures): 30 miles per hour to kilometers per minute
.8 km/min
Verify the following chemical equation is balanced. 2Mg + O2 → 2MgO With 0.5 moles of O2, how many moles of Mg would be needed to react? (Write only the number of moles in the blank to answer the question! For example, write 3 not 3 moles.)
1
Identify the set of coefficients that balances the equation___H2O + ___CO → ___CO2 + ___H2
1,1,1,1
Solve for the following using the correct number of significant figures. 8.78 m * 2.5 m = _______ m2
22
Identify the set of coefficients that balances the equation___H2 + ___N2 → ___NH3
3,1,2
Identify two (2) physical properties that a polar compound and a non-polar compound would differ on.
Solubility Melting point
What statements are always true about limiting reactants?
The limiting reactant is completely used up in the reaction. The limiting reactant dictates the amount of product. There will be an excess of other reactants at the end of the reaction.
What is the equivalence point in an acid-base titration experiment?
The point at which the moles of base equals the moles of acid
Write the chemical name for: NiCl2
nickel(II)chloride
a liquid consisting of one substance dissolved in another
solution
What is the molarity of a solution prepared by dissolving 12 g of HCl in enough water to make 742 mL of solution?
.44
What is the osmolarity of a solution containing 0.1 M NaNO3 and 0.2 M NaCl?
.6
What is the density of a substance (g/mL) where 1.524 gallons has a mass of 3,467.0 grams? 1 gallon = 3785.5 mL
.601
Verify the following chemical equation is balanced TiO2 + 3C → Ti + 2CO If you begin with 36 grams of carbon, how many moles of C does that make?
3
Verify the following chemical equation is balanced. 2Mg + O2 → 2MgO With 6 moles of Mg, how many moles of O2 would be needed to react? (Write only the number of moles in the blank to answer the question! For example, write 3 not 3 moles.)
3
What is the correct reading of the volume in the pictured buret? Make sure to report your reading with the appropriate significant figures.
39.95 mL
Antacids neutralize the hydrochloric acid in your stomach. What is the correct neutralization reaction of stomach acid with DiGel (Al(OH)3)(Al(OH)X3) ?
3HCl+Al(OH)3⟶3H2O+AlCl3
Determine how many significant figures are in the following number: 0.06589.
4
Verify the following chemical equation is balanced. 2Mg + O2 → 2MgO With 2 moles of O2, how many moles of MgO will be produced? (Write only the number of moles in the blank to answer the question! For example, write 3 not 3 moles.)
4
Verify the following chemical equation is balanced TiO2 + 3C → Ti + 2CO If you begin with 88.2 kilograms of TiO2, how many kilograms of Ti can you make?
52.9 kg of Ti
A balloon is inflated outside on a cool morning. As the temperature rises, reaching its peak in the afternoon, the volume of the balloon will increase.
As the temperature cools down again in the evening, the volume of the balloon will decrease.
Predict the ionic compound that would form when each of these two ions come together: Ca and P
Ca3P2
For the following forward chemical equation, identify the acid/base/conjugate acid/conjugate base. NH3+HCl−⇀↽−Cl−+NH4+NHX3+HCl↽−−⇀ClX−+NHX4X+
HCL-A NH4-CA Cl--CB NH#-B
Identify whether each substance is an acid or base.
RbOH-B HCLO4-A HNO2-A KOH-B Ba(OH(2-B
If you want to return the two liquids to the same height in the tube, apply a pressure equal to the osmotic pressure to the solution on the
right side of the tube.
a liquid that dissolves another substance
solvent
Identify two covalent compounds that are present in your home.
sugar vegetable oil
What is the osmolarity of a solution containing 0.2 M NaNO3 and 0.3 M sucrose?
.7
Aluminum has a density of 2.70 g/cm3. What is the mass (g) of aluminum foil that has a volume of 48.9 cm3?
132 g
Antacids neutralize the hydrochloric acid in your stomach. What is the correct neutralization reaction of stomach acid with Milk of Magnesia (Mg(OH)2)(Mg(OH)X2) ?
2HCl+Mg(OH)2⟶2H2O+MgCl22HCl+Mg(OH)X2⟶2HX2O+MgClX2
What is the percent-by-mass, %(m/m), concentration of Na2SO4 in a solution made by dissolving 35.2 g of Na2SO4 in enough water to give 96.0 g of total solution?
36.7
Consider the balanced equation for the combustion of benzene, C6H6CX6HX6 . 2C6H6+15O2⟶12CO2+6H2O2CX6HX6+15OX2⟶12COX2+6HX2O What molar ratio will appear when calculating the amount of O2OX2 needed to react with a given amount of C6H6CX6HX6 ?
15 mol O2 2 mol C6H6
When completing the reaction of ammonia with water, fill in the coefficients and products.
1OH-+1NH4+
Which sample would have the most atoms of oxygen present?
2.00 moles of Al2O3
What is the mass (in g) of 7 atoms of helium?
4.65 x 10-23
How do you determine the last digit in any measured number on a non-digital instrument?
Estimate one digit past the smallest precisely known digit or marking.
For the following concentrations, determine if the solutions are acidic, basic, or neutral and select the best answer from the subsequent choices. a. [H3O+]=0.15 M b. [OH-]=0.0045 M c. [OH-]=1.25 x 10-10 M
a=acidic; b=basic; c=acidic
Describe the following as acidic, basic, or neutral: Lemon juice Select one:
acidic
a value used to describe the amount of one substance dissolved in another
concentration
Select the best description of H2SO4.
diprotic acid
How many grams of KOHKOH are needed to neutralize 10.8 mL of 0.15 M HClHCl in stomach acid?
0.091
Verify the following chemical equation is balanced TiO2 + 2C → Ti + 2CO If you begin with 28.6 kilograms of carbon, how many moles of Ti can you make?
1.19 x 103 moles of Ti
Determine the formula mass for C7H16N.
114.24
How many grams of glucose (C6H12O6) are there in 911.47 mL of a 15.63 %(m/v) glucose-water solution?
142.5
Verify the following chemical equation is balanced N2 + 3H2 → 2NH3 If you begin with 14 grams of N2, how many grams of NH3 can you make?
34
A sample of air has 3.55 moles of N2 and 2.50 moles of O2. What is the total pressure for the sample of air described, if the volume is 29.51 L and the temperature is 300 K?
5.06 atm
What is the mass of NaCl in 51.2 mL of a 10.0% w/v solution?
5.12 g
Convert the following (to the appropriate number of significant figures): 2.953 km / 53.9 m = _____________ (the answer has no units)
54.8
Choose the best summary of the octet rule.
Elements are inclined to bond in a manner that gives them eight electrons in their valence shell.
Solution with lower solute concentration than the solution in the cell
Hypotonic
Consider two solutions; one of a weak acid and one of a strong acid. How is it possible that a solution of weak acid can have a lower pH than a solution of strong acid?
The concentration of the weak acid is greater than the concentration of the strong acid.
After assembling a gravity filtration apparatus, begin the separation of a mixture by decanting it into the filter paper. Pour the entire contents of the mixture into the filter paper, stirring the solid in the filter paper if needed to speed up the filtration. After all the liquid has drained through the filter paper, finish by rinsing the solid with solvent.
After a mixture has been poured through filter paper, the solid component remains on top while the liquid flows through. To collect the solid, spread the filter paper on a watch glass and allow the solvent to evaporate.
Which of the following compounds are insoluble in water?
MgCO3 Al2S3 PbBr2
Predict the ionic compound that would form when each of these two ions come together: Mg and Cl
MgCl2
Fill in the steps for an experimental procedure to measure out 3.50 moles of DI water into a 400 mL beaker given any equipment available in your lab drawer. [Hint: You cannot measure out 3.50 moles of water with the electronic balances in our lab. You will need to convert the units of moles into something else that you can measure out accurately. You may need to use the density of water in your calculations.]
Obtain a clean and dry graduated cylinder add 63.1 mL to glassware
Predict what happens when a base (OH-) is added to a buffer solution containing an equal mixture of a weak acid HA and its conjugate base A-. The pH of the solution will increase.
The concentration of the conjugate base A- will increase. The concentration of the weak acid HA will decrease.
Sublimation is a phase change from solid to gas.
The liquid phase is not present in this change.
Identify which balance was used to make each mass reading. 5.43 g 6.539 .90 4.000 1.230
balance with ±0.01 g tolerance A balance with ±0.001 g tolerance A balance with ±0.01 g tolerance A balance with ±0.0001 g tolerance A balance with ±0.001 g tolerance
When blood cells are placed in a 1.50% (m/v) solution of NaCl, this is considered:
hypertonic
Solution with equal solute concentration to the solution in the cell
isotonic
For a beaker containing the reaction below that is at equilibrium, using LeChatelier's principle, predict which way the equilibrium conditions will shift if silver chloride was added to a beaker. AgNO3(aq)+NaCl(aq)⟶AgCl(s)+NaNO3(aq)AgNOX3(aq)+NaCl(aq)⟶AgCl(s)+NaNOX3(aq)
left
2 cups of milk 2 avocados 144 grams of sugar 3 teacups 18 meters 1 ft=12 in
measured exact measured exact measured exact
For a beaker containing the reaction below that is at equilibrium, using LeChatelier's principle, predict which way the equilibrium conditions will shift if the concentration of sodium chloride is increased. AgNO3(aq)+NaCl(aq)⟶AgCl(s)+NaNO3(aq)AgNOX3(aq)+NaCl(aq)⟶AgCl(s)+NaNOX3(aq)
right
You are buying drinks for a party for the upcoming weekend. A gallon of milk is on sale for $2.99. A two-liter bottle of soda is on sale for $0.99 and a bottle of apple juice is on sale for $1.99 for 64 ounces. Which drink is the best value for your party?
soda
For the following chemical equation, which answer best represents the equilibrium constant K? 2A+B__> 2X+Y
([x]2×[y]) ([a]2×[b])
For the following chemical equation, which answer best represents the equilibrium constant K? A+B↽−−⇀X+Y
([x]×[y]) ([a]×[b])
Identify five (5) characteristics of bromine.
red-brown liquid at room temperature strong scent halogen reactive with metals
Convert the following (to the appropriate number of significant figures): 28 miles per hour to kilometers per minute
.75 km/min
Convert 34 m to km.
0.034 km
Solve for the following using the correct number of significant figures. 7.7 g / 108.83 mL = _______ mL
0.071
What is the value of the gas constant, R, in units of L⋅atmmol⋅KL⋅atmmol⋅K ?
0.0821
Convert 228 mg to g.
0.228 g
Calculate the volume of a metal cylinder that has a diameter of 0.95 cm and a height of 1.91 cm.
1.4 cubic centimeters
Solve for the following using the correct number of significant figures. 355.8 g + 0.736 kg = _______g
1092
Select the coefficients necessary to balance the neutralization reaction. Choose a coefficient for every compound.
1H2SO4+HX2SOX4+ 2 KOH⟶KOH⟶2 H2O+HX2O+ 1K2SO4
Determine how many significant figures are in the following number: 6.7 x 103.
2
What is the osmotic pressure (in atm) of a 0.197 L solution containing 0.700 g of CaCl2CaClX2 at 295 K? The molar mass of the solute is 110.98 g/mol and the value of the gas constant, RR , is 0.0821 L-atm/mol-K.
2.33
The temperature of a room is 23.7 °C. What is this temperature expressed in Kelvin (K)?
296.9
Determine how many significant figures are in the following number: 20.0.
3
Determine how many significant figures are in the following number: 8.60 x 104.
3
Consider the balanced reaction of magnesium and oxygen. 2Mg+O2⟶2MgO2Mg+OX2⟶2MgO What mass of MgO can be produced from 1.93 g of Mg and 2.07 g of O2?
3.2 g
Suppose a 12.6 g potato slice is soaked in solution. After it is removed, the mass of the potato is 18.9 g. What is the percent change in mass?
50%
Convert the following (to the appropriate number of significant figures): 13.6 meters to inches
535 inches
Choose the best graduated cylinder to make each measurement in a single use. 36 mL of water 5.75 mL of a sucrose solution 18.5 mL of a NaCl solution
A 50 mL graduated cylinder with markings every 10 mL A 10 mL graduated cylinder with markings every 0.1 mL A 25 mL graduated cylinder with markings every 1 mL
This is the process of separating a solid from a liquid by means of a porous material.
Filtration
Solution that causes water to move out of the cell
Hypertonic
Solution that causes water to move into the cell
Hypotonic
Suppose you are collecting a gas over water at 23 oC and obtain a pressure reading of 780.7 mm Hg.If the vapor pressure of water is 21.1 mm Hg at the collection temperature, what is the pressure of the collected gas?
Pgas=780.7 mm Hg−21.1 mm HgPgas=780.7 mm Hg−21.1 mm Hg
Consider the balanced equation of KIKI reacting with Pb(NO3)2Pb(NOX3)X2 to form a precipitate. 2KI(aq)+Pb(NO3)2(aq)⟶PbI2(s)+2KNO3(aq)2KI(aq)+Pb(NOX3)X2(aq)⟶PbIX2(s)+2KNOX3(aq) What mass of PbI2PbIX2 can be formed by adding 4.00 g of KIKI to a solution of excess Pb(NO3)2Pb(NOX3)X2 ?
Start by finding the moles of KI using its molar mass. moles of KI=4.00 g KI×1 mol KI166.0 g KImoles of KI=4.00 g KI×1 mol KI166.0 g KI Then use the molar ratio between KI and PbI2 to find the moles of PbI2. moles of PbI2=moles of KI×1 mol PbI22 mol KImoles of PbIX2=moles of KI×1 mol PbIX22 mol KI Finally, use the molar mass of PbI2 to find the mass of PbI2. mass of PbI2=moles of PbI2×416.0 g PbI21 mol PbI2mass of PbIX2=moles of PbIX2×416.0 g PbIX21 mol PbIX2
liquid
Takes the shape of its container Maintains a constant volume High density
The H2HX2 produced in a chemical reaction is collected through water in a eudiometer. If the pressure in the eudiometer is 760.0 torr and the vapor pressure of water under the experimental conditions is 23.1 torr, what is the pressure (torr) of the H2HX2 gas?
The total pressure is equal to the pressure of the water vapor plus the pressure of the hydrogen gas. Ptotal=PH2O+PH2Ptotal=PHX2O+PHX2 Subtract the pressure of the water vapor from the total pressure to find the pressure from the H2HX2 . Ptotal−PH2O=PH2Ptotal−PHX2O=PHX2 760.0 torr−23.1 torr760.0 torr−23.1 torr
Why are these answers different for the number of minutes in a month?
There is a discrepancy in the number of days per month.
When describing the uncertainty of a measurement, the term ------ refers to the closeness between a measurement and its accepted value, whereas the term ----- refers to the closeness among a set of measurements.
accuracy, precision
The pressure is kept constant, while the temperature is decreased. What will happen to the volume?
decrease
The volume and temperature remain constant, while some of the gas is let out of the container. What will happen to the pressure?
decrease
A solvent is added to dissolve only one mixture component and then the liquids are separated.
extraction
Containing a stirred reaction mixture
flask
capable of measuring a range of volumes of liquid designed to measure one specific volume of liquid used for applications in which great accuracy is needed
graduates volumetric volumetric
are combinations of two or more substances.
mixtures
Consider the reaction of propane with oxygen. C3H8+5O2⟶3CO2+4H2OCX3HX8+5OX2⟶3COX2+4HX2O How many moles of CO2COX2 molecules are produced when 1.6 moles of O2OX2 molecules react completely?
mol CO2 produced=1.6 mol O2×3 mol CO25 mol O2
Dalton's Law of Partial Pressures states that the total pressure of a gas mixture is equal to the sum of the
partial pressures of all the component gases as long as the gases do not react with each other.
The comparison of the experimental amount of product to the calculated amount
percent yield
The components of a mixture are separated based on their properties
physical
The pressure and the temperature are both decreased by 50%. What will happen to the volume?
stay the same
Whereas pure substances have fixed compositions,
the composition of mixtures can vary
Convert 81.39 dL to mL.
8139 mL
Which set is from the same isoelectric series?
Al3+, Mg2+, Na1+, F1-
Predict whether the following salt is acidic, basic, neutral, or can't tell. NaCN Select one:
acidic
Write the chemical formula for chromium (IV) oxide.
CrO2
According to your textbook, how many of the following are properties of covalent compounds? Can be gas, liquid, or solid at room temperature. Does not conduct electricity. Exist as an extended array of atoms. Involves the sharing of electrons.
three
Solid:
Keeps its shape Maintains a constant volume High density
Each of the substances in the mixture retains its
chemical identity
What is the molarity of the solution prepared by diluting 25.3 mL of 2.10 M AgNO3 to the final volume 98.5 mL? Calculate your final answer to 2 decimal places.
.54
Draw a Lewis structure for CO32-. How many double bonds are present in the structure?
1
Fill in each description with the correct type of intermolecular force.
1. Dipole-dipole forces are an attraction between a positive region of a polar molecule and a negative region of another polar molecule. 2. London forces are attractions between temporary dipoles. 3. Hydrogen bonds are attractions between the -H of one molecule and an electronegative atom on another molecule.
What is the pH of a solution of 1.00 L of water with 0.0387 moles of HNO3 in it?
1.41
What is the price per gallon of the most cost-effective choice?
1.87
What is the pH of a solution of 1.00 L of water with 0.0685 moles of KOH in it?
12.8
What is the volume (cm3) of a sample of aluminum that has a mass of 338 g? (The density of aluminum is 2.70 g/cm3.)
125
How many milliliters of a 0.619 M KOH solution would be needed to provide 5.36 g of KOH to a chemical reaction?
154
Select the coefficients necessary to balance the neutralization reaction. Choose a coefficient for every compound.
2 HCl+1 Ca(OH)2-> 2 H2O + 1 CaCl2
What is the pH of a solution of 1.00 L of water with 0.00506 moles of HCl in it?
2.30
Verify the following chemical equation is balanced N2 + 3H2 → 2NH3 Given 68.5 grams of nitrogen, how many moles of nitrogen are present?
2.44
Solve for the pH of a buffer solution using the Henderson-Hasselbalch equation that is (pg. 309). A 1.0 L solution of 0.32 M HNO2 and 0.20 M NO22- constitutes a buffer solution. The Ka of HNO2 is 6.8 x 10-4. HINT: A is the concentration of the conjugate base and HA is the concentration of the weak acid. Do not forget to convert Ka to pKa.
2.96
Convert 56 Celsius to Kelvin.
329.15
Solve for the following using the correct number of significant figures. 8.30 m * 4.0 m = _______ m2
33
Determine how many significant figures are in the following number: 0.04790.
4
There are 24 hours per day, 60 minutes per hour, 7 days per week, and 4 weeks per month. How many minutes are in a month?
40320
Solve for the following using the correct number of significant figures. 76.44 m - 35.293 m = _________ m
41.15
There are 365 days per year, 24 hours per day, 12 months per year, and 60 minutes per hour. How many minutes are in a month?
43800
Use the ideal gas law to solve for the moles of gas that occupies 25.61 L at 5.13 atm and 27 °C.
5.32
Solve for the following using the correct number of significant figures. 2.668 km / 52.3 m = _______
51.0
Convert the following (to the appropriate number of significant figures): 33.64 miles to kilometers
54.14
Solve for the following using the correct number of significant figures. 14.825 mL + 18.5 mL + 25.37 mL = _________ mL
58.7
Verify the following chemical equation is balanced. 2Mg + O2 → 2MgO With 3 moles of O2, how many moles of Mg would be needed to react? (Write only the number of moles in the blank to answer the question! For example, write 3 not 3 moles.)
6
Solve for the following using the correct number of significant figures. 49.59 g + 15.7 g = _________
65.3
Convert the following (to the appropriate number of significant figures): 19.4 meters to inches
764 inches
Verify the following chemical equation is balanced N2 + 3H2 → 2NH3 If you begin with 280 grams of H2, how many moles of NH3 can you make?
93.3
Which of the following would not be helpful in separation a mixture of sand and salt?
A magnet would not be helpful in separating a mixture of sand and salt.
Consider the balanced equation for the reaction of aluminum with hydrochloric acid. 2Al+6HCl⟶2AlCl3+3H22Al+6HCl⟶2AlClX3+3HX2 Fill in the conversion factors required to calculate the mass of HCl needed to react with 5.00 g of Al. 5.00 g Al×( A )26.9815 g Al×( B )( C )×( D )1 mol HCl=20.3 g HCl5.00 g Al×( A )26.9815 g Al×( B )( C )×( D )1 mol HCl=20.3 g HCl
A-1 mol Al B-6 mol HCl C-2 mol Al D-36.454 g HCl
Identify the ideal value of the van't Hoff factor for aqueous solutions of each solute.
C12H22O11-1 NaCl-2 CaCl2-3 C2H6O-1 Na2SO4-3 NH4Cl-2
What is the correct molecular formula for calcium chloride?
CaCl2
Determine the ion that would satisfy the octet rule for chlorine.
Cl^1-
Using the guidelines from pages 119-123 of your textbook (Section 4.9 and 4.10), how many of the following bonds would be considered polar covalent bonds? Check all that apply. Select one or more:
H bonded to N N bonded to O
The boiling points for H2O (BP=100 °C) and H2S (BP=-60 °C) are drastically different despite oxygen and sulfur being next to each other on the periodic table. Choose the best explanation for this difference.
H2O can hydrogen bond, whereas H2S cannot. This strong intermolecular force makes it more difficult for the H2O molecules to transition from the liquid to the vapor phase.
Identify three ways you could increase the rate of an aspirin tablet dissolving in a glass of water.
Heat the water. Crush the aspirin tablet. Stir the mixture.
Order the three types of intermolecular forces (dipole-dipole, London force, hydrogen bonds) in order from weakest to strongest.
London forces (weakest) Dipole-dipole forces Hydrogen bonds (strongest)
What is the correct molecular formula for magnesium bromide?
MgBr2
For the chemical NH2CO2H, where N is bound to C and the 2 H's (H2N-C), each O is bound to C and the final H is on an O (O-H), create a Lewis structure. Which of the following is a correct description of the O without the H attached?
One double bond and two pairs (four dots) of electrons
What is the equilibrium expression (K= ) for the following reaction? AgNO3(aq)+NaCl(aq)⟶AgCl(s)+NaNO3(aq)AgNOX3(aq)+NaCl(aq)⟶AgCl(s)+NaNOX3(aq) Select one:
[NaNO3] [AgNO3][NaCl]
Predict whether the following salt is acidic, basic, neutral, or can't tell. NH4Br Select one:
acidic
The amount of product experimentally produced
actual yield
What is the correct description of the shape and polarity of H2O?
angled, polar
What is the shape on the center atom for SO2?
angular
Classify the following chemical reaction as a combination, decomposition, single-replacement, double-replacement, or combustion reaction: 2C2H6 + 7O2 → 4CO2 + 6H2O
combustion
An _________________ chemical reaction is a chemical reaction in which heat is produced.
exothermic
A solid is caught on paper or a membrane while the liquid passes through.
filtration
measuring out a volume of liquid
graduated cylinder
What is the correct units for formula mass (also known as molecular mass)?
grams/moles
For the following forward chemical equation, identify the acid/base/conjugate acid/conjugate base. H2SO4+KOH−⇀↽−H2O+KHSO4HX2SOX4+KOH↽−−⇀HX2O+KHSOX4
h20-CA H2SO4-A KOH-B KHSO4-CB
For the following forward chemical equation, identify the acid/base/conjugate acid/conjugate base. HCO3−+H2O−⇀↽−OH−+H2CO3HCOX3X−+HX2O↽−−⇀OHX−+HX2COX3
h20-acid oh-- CB HCO3--B H2CO3-CA
a chemical that is dissolved
solute
A solid mixture is heated. One component transitions directly between solid and gas.
sublimation
Identify the pieces of glassware that are most effective for accurate solution preparation.
volumetric flask volumetric pipet
A neutralization reaction is a reaction between an acid and a base that results in the formation of
water and a salt