chem part 2

A reaction that absorbs heat is endothermic. What will be the sign of ΔH?

+

What is the sign of ΔH for a reaction that is exothermic

-

Consider the following chemical equations. C(s)+O2(g)→CO2(g)CO2(g)→CO(g)+12O2(g)ΔHΔH=−394kJmol=283kJmol Use the equations above and Hess's Law to calculate the standard enthalpy of formation for CO(g). The reaction for the formation of CO is represented by the equation below. C(s)+12O2(g)⟶CO(g)ΔH=?

-111

Given that the standard enthalpy of formations for NH3=−46.1kJmol, HCl=−92.3kJmol, and NH4Cl=−314.4kJmol, calculate the standard enthalpy change for the reaction. NH3(g)+HCl(g)⟶NH4Cl(s)

-176

NH3(g)+HCl(g)⟶NH4Cl(s) Given the standard enthalpies of formation (below), calculate the enthalpy change for the reaction in kilojoules. NH3HClNH4ClΔH∘f=−46.1kJmolΔH∘f=−92.3kJmolΔH∘f=−314.4kJmol

-176

Hydrogen gas, H2, reacts explosively with gaseous chlorine, Cl2, to form hydrochloric acid, HCl(g). What is the enthalpy change, in kilojoules, for the reaction of 1 mole of H2(g) with 1 mole of Cl2(g) if both the reactants and products are at standard state conditions?

-184.6

Graphite has a specific heat capacity of 0.709Jg ∘C. Determine the change in energy in joules if a 25.0 g sample of graphite has a temperature change of −17.0 ∘C.

-301

Calculate ΔH∘298 in kilojoules for the process: Sb(s)+52Cl2(g)⟶SbCl5(g) Given the information below: Sb(s)+32Cl2(g)⟶SbCl3(g)ΔH∘298=-314 kJSbCl3(g)+Cl2(g)⟶SbCl5(g)ΔH∘298=-80.0 kJ

-394

Consider the following chemical equations to answer the question that follows. CaCO3(s)Ca(OH)2(s)Ca(OH)2(s)+2HCl(g)→CaO(s)+CO2(g)→H2O(l)+CaO(s)→CaCl2(s)+2H2O(l)ΔHΔHΔH=175kJ=67kJ=−198kJ Using the information above, determine the change in enthalpy for the following chemical reaction. CaCO3(s)+2HCl(g)⟶CaCl2(s)+H2O(l)+CO2(g)

-90

A solution has a concentration of 0.53 M KBr and a volume of 0.044 L. It is then diluted to a volume of 0.083 L. What is the new concentration?

.28m

A solution has a concentration of 1.6 M and a volume of 0.175 L. If the solution is diluted to 1 L, what is the new concentration?

.28m

Consider the reaction described by the following chemical equation. 2Ag2S(s)+2H2O(l)⟶4Ag(s)+2H2S(g)+O2(g)ΔH∘rxn=595.5kJmol The change in enthalpy for this reaction can be determined theoretically by using the standard enthalpies of formation for the species involved. ΔH∘rxn=∑nΔH∘fproducts−∑nΔH∘freactants What is the value for the standard enthalpy of formation for Ag(s) that would be used in the equation above?

0

What is the standard enthalpy of formation for an element in its most stable form?

0

Calculate the volume needed of a stock solution that has a concentration of 4.2 M and is then diluted to 0.034 L of 0.66 M solution.

0.0053

solution has 0.45 M of FeSO4. How many moles of FeSO4 are in a 20 mL drop of this solution

0.009

How many moles of Na2CO3 are present in 0.010 L of a 2.0 M solution?

0.020 mol

A solution of NiCl2 with a volume of 50 mL and concentration of 0.10 M is diluted to a volume of 0.10 L. What is the concentration of the resulting solution?

0.05 M

A stock solution has a concentration of 1.5 M NaCl and is diluted to a 0.80 M solution with a volume of 0.10 L. What volume of the stock solution in liters was used to make the diluted solution?

0.053

A stock solution has a concentration of 1.5 M SO2 and is diluted to a 0.54 M solution with a volume of 0.18 L. What was the volume of the stock solution?

0.065

A 100.0 mL sample of water at 0∘C is exposed to a certain gas at a pressure of 20.26 kPa. This results in the dissolution of 1.45×10−3 g of the solute. Use Henry's law (shown below) to determine the solubility of this gaseous solute when its pressure is 101.3 kPa.

0.0725 g/L

A solution has a concentration of 0.8 M and contains 15 g AgBrO3. What is the volume of the solution?

0.08

A solution with a volume of 150 mL that is 0.20 M SO2 is diluted to a volume of 300 mL. What is the concentration of the resulting solution?

0.10 M

What is the concentration of the solution that results from diluting 25.0 mL of a 2.04 M solution of CH3OH to 500.0 mL?

0.102m

156 g C12H22O11 (sucrose) is dissolved into 4.0 L of solution. What is the molar concentration of the solution? Report your answer with the correct number of significant figures.

0.11

A 0.15 M NaOH solution has a volume of 0.125 L but is then diluted to 0.15 L. What is the concentration of the new solution?

0.125 M

A 0.32 M NH4OH solution has a volume of 0.20 L, but it is diluted to a volume of 0.50 L. What is the concentration of the new solution?

0.13m

A solution of KOH is prepared by diluting a 1.0L solution of 0.40MKOH to a volume of 3.0L. What is the concentration of the diluted solution?

0.13m

A 0.15 M NaOH solution has a volume of 0.125 L and is diluted to 0.125 M. What is the volume of the new solution, in liters?

0.15l

A solution has a concentration of 3.0 M and a volume of 0.20 L. If the solution is diluted to 4.0 L, what is the new concentration, in molarity

0.15m

What is the molar concentration of a a 5.00 L solution that contains 0.800 mol of magnesium acetate?

0.160 M

Calculate the concentration of a solution prepared by diluting 0.0668 L of 0.235 M Ca(NO3)2 solution to a volume of 0.0872 L.

0.18 M

A 0.5 M solution contains 0.1 mol of AgCl. What is the volume of the solution

0.2

What is the molarity of a 0.40 L solution with 6.2 g KCl?

0.21

Calculate the concentration of a solution prepared by diluting 0.058 L of 0.28 M SiF6 solution to a volume of 0.075 L.

0.22m

A scientist has 0.175 L of a 1.6 M solution of LiCl. He wants to dilute the solution to 1.0 L. What is the concentration of the new solution?

0.28 M

A stock solution has a concentration of 0.25 M NaOH. It is diluted to a 0.15 M solution with a volume of 0.5L. What is the volume of the original stock solution?

0.3l

A 2.5 M solution of KBr has a volume of 0.10 L. In order to make this a 0.55 M solution, what should the final volume be?

0.45l

A solution has a concentration of 0.70 M NaOH and a volume of 0.020 L. It is then diluted to a volume of 0.030 L. What is the new concentration, in molarity?

0.47m

What is the molarity of a solution if there are 67 g ZnCl2 per liter?

0.49

What is the molarity of a 500. mL solution containing 10. g NaOH

0.5

Calculate the molarity of a solution prepared by diluting a 1.5 L solution of 0.70 M CaCl2 to 2.0 L

0.525 M

A 2.5 M solution of KBr has a volume of 0.10 L. If the solution is diluted to 0.45 L, what is the new concentration?

0.56 M.

You have 12.1 L of a 1.3 M sucrose (C12H22O11) solution. You dilute the solution until you have 25.2 L. What is the concentration of the 25.2 L solution?

0.6 M

How many moles of of Al2O3 are in 1.5 L of a 0.42 M solution?

0.63

Calculate the volume, in liters and to the hundredths place, of a stock solution that has a concentration of 0.235 M Ca(NO3)2 and when diluted to a 0.872 L becomes 0.18 M Ca(NO3)2.

0.665l

A 6 M solution of CaCl2 has a volume of 0.1 L. If the solution is diluted to 0.9 L, what is the new concentration?

0.67 M

A 1.5 M solution of NaCl has a volume of 0.534 L. If the solution is diluted to 1.0 L, what is the new concentration

0.80m

2.5 M solution contains 300. g of SF6. What is the volume of the solution?

0.82

Calculate the concentration of a solution prepared by diluting 6.929 mL of 3.55 M solution to a volume of 29.93 mL

0.82m

Calculate the molarity of a solution prepared by diluting 7.0 mL of 4.0 M solution to a volume of 30 mL.

0.93 M

What is the molar concentration of a 300.0 mL solution containing 5.00 g of NH3?

0.979

What is the molarity of a 1.22 L solution made with 1.2 moles of calcium carbonate

0.984 M

A solution of 4.8 M KNO3 has a volume 2.5 L. If the solution is diluted to 10.0 L, what is the new concentration?

1.2 M

A solution of 3.51 M NiCl2, has a volume of 4.57 L. If the solution is diluted to 12.5 L, what is the new concentration?

1.28m

What is the molarity of a 400 mL solution containing 0.60 moles of NaCl

1.5

A 12 M solution of KNO3 has a volume of 0.50 L. If the solution is diluted to 4.0 L, what is the new concentration?

1.5m

In the heat formation equation for sodium chloride (NaCl), what would be the coefficient for chlorine (Cl2)

1/2

In the heat of formation equation for H3PO4, what would be the coefficient for the most stable state of phosphorus (P4)?

1/4

What is the mass percentage of 38.2 g of calamine in a 349 g solution?

10.9

A bottle of soda contains 39 grams of sucrose (C12H22O11) and 300 grams of water (H2O). What is the percent mass of sucrose in this soda?

11.5

A solution contains 35 g of ammonium nitrate in 250 g of water. What is the mass percentage of ammonium nitrate in this solution?

12

24 g of iron sulfate are dissolved in 152 mL of solution. What is the mass-volume percentage of this solution?

16

In a thermochemical equation, if the stoichiometric coefficients of the compounds are doubled, the change in enthalpy must be multiplied by what number?

2

What volume of the same 0.45 M solution of FeSO4 solution contains 1 mole of the FeSO4 solute?

2.22 L

A 1.38 mL sample of solution has a concentration of 18.0 M. What mass of H2SO4, in grams, is contained in this sample

2.44

How many moles of NaOH are in 0.25 L of a 10.0 M solution?

2.5

In order to have a solution of 1.2 M KNO3, 10 L are needed. What volume is necessary to make this from a 4.8 M solution?

2.5 L

734 g of Li2SO4 is dissolved in a 2510 mL solution. What is the concentration of the solution? Report your answer with the correct number of significant figures.

2.66 M

What is the mass of Ba(OH)2 present in a solution with a concentration of 3.00 M and a volume of 460.0 mL?

236

If the heat of combustion of carbon monoxide (CO) is −283.0 kJmole, how many grams of carbon monoxide must combust in order to release 2,500.kJ of energy

247.4g

What is the percent mass of potassium chloride in a solution made by adding 25 g of potassium chloride to 70.0 ml of water?

26

What is the mass, in grams, of NaCl in 1.0 L of a 0.479 M solution?

28

A solution is made by mixing 38 mL of ethanol and 100 mL of toluene. What is the volume percentage of ethanol in the solution?

28%

Calculate the volume, in milliliters, of a solution prepared by diluting a 3.55 M solution with a volume of 6.929 mL to 0.823 M.

29.9ml

What is the heat of formation reaction for acetic acid (CH3COOH)?

2C +2H2+O2→CH3COOH

In the heat of formation equation for CH3CH2OH, what would be the coefficient for hydrogen gas?

3

What is the mass-volume percentage of a solution of 1.50g of solute dissolved in water to make 50.0mL of solution?

3

How many moles of HCl are in 0.25 L of a 12 M solution?

3.0

What is the volume in liters of a 1.50 M solution containing 200 g NaOH

3.33

A 52 mL solution made with 18 mL of toluene in acetone has what volume percentage of toluene?

35

A solution is 17 mL ethanol in 48 mL of solution. What is the percent volume of ethanol in this solution?

35

What is the volume percentage of ammonium hydroxide if a solution contains 28 mL of ammonium hydroxide in 53 mL of water?

35

Calculate the final volume of a solution prepared by diluting a 4.0 M solution with a volume of 7.0 mL to 0.80 M in milliliters.

35ml

A solution is made by adding 120 g of citric acid to 210 g of water. What is the percent mass of citric acid in this solution

36.4%

How many moles of Li2SO3 are in 2.04 L of a 2.29 M solution

4.67

How many grams of AgCl would be needed to make a 4.0 M solution with a volume of 0.75 L?

430

93.0 g of a solute in 204 mL of solution has what mass-volume percentage?

46

The enthalpy of formation for ammonia (NH3) is −46.19 kJ/mol. What does this mean?

46.19 kJ of energy are released for every mole of ammonia that is formed from its elements in their most stable states under standard conditions.

A 0.25 L solution with 93.2 g of KCl has a molarity of

5.0

What is the volume of a solution, in milliliters, that contains 1.5 g LiNO3 and has a concentration of 0.40 M?

54ml

A solution is made by adding 5.01 g of iron sulfate to 75.3 g of water. What is the mass percentage of iron sulfate in this solution?

6.24

How many moles of Li2SO3 are in 2.1 L of a 3.0 M solution?

6.3

What is the mass percentage of 28.7 g of boric acid in a 47.5 g solution?

60.4

How many moles of Si2N4 are in 3.5 L of a 2 M solution

7

At 25.0∘C and 1.00 atm, as much as 1.45 g of carbon dioxide can dissolve in 1.00 L of water. At 25.0∘C and 5.00 atm, how many grams of CO2 can dissolve in 1.00 L of water

7.25

What is the volume (in milliliters) of a 4.0 M solution containing 3.06 g of H2SO4?

7.8ml

If a chemical equation has a ΔH=−75.5 J, what is the ΔH when the reaction is reversed?

75.5

If the heat of combustion of hydrogen gas (H2) is −285.8kJmol, how many grams of H2 must combust in order to release 1.2×103kJ of heat?

8.5g

The molarity of sucrose in a sweetened tea is 0.05M. What volume (in mL) of this tea contains the same amount of sugar (in mol) as 10 mL of the soft drink from the example above, which contained 0.004 mol of sugar?

80

Which of the following is an example of a covalent network crystalline solid?

C

Which substance is considered a molecular solid?

CO2

In forming a solution, the solute always:

Dissolves

Which of the following is not characteristic of a solution?

Its physical state is generally the same as that of the solute.

Choose the option below that is characteristic of a solution.

Its physical state is generally the same as that of the solvent.

Considering the steps involved in dissolution, which of the following do you expect to speed up a dissolution process? Select all that apply.

Stirring the solution vigorously Grinding the solute down into tiny particles Gently heating the solution

Which of the following is equal to the solubility of a solute in a particular solvent?

The maximum equilibrium concentration of solute that can be achieved. The concentration of solute in a saturated solution.

When a solution is saturated and additional solute sits at the bottom of the vessel:

The solute will continue to dissolve and precipitate at precisely the same rate so that the concentration will remain fixed.

The aqueous solutions below contain equal moles of copper(II) nitrate. Which is more dilute?

The solution on the right

Classify each substance in the table as either a metallic, ionic, molecular, or covalent network solid:

X = ionic; Y = metallic; Z = covalent network

Which of these substances will NOT form a covalent network solid?

carbon dioxide

Why do metallic solids conduct electricity so well?

delocalized electrons

Dissolution is an _______ process.

depends on the solution

Hess's law can be used to accurately calculate the change in enthalpy of a reaction because:

enthalpy is a state function

We can dilute an aqueous solution by adding liquid water to the solution, resulting in a less concentrated solution. Which of the following would result in a more concentrated solution?

evaporating some of the water contained in the solution

The component of gasoline that gives it such a high enthalpy of combustion is:

hydrocarbons

The proportionality constant in Henry's law depends on the:

identity of the solute identity of the solvent temperature

Which type of solid is typically brittle

ionic solid

What kinds of substances typically form amorphous solids?

large neutral molecules

The ratio of a solute's mass to the solution's volume expressed as a percentage is known as:

mass-volume percent

Which of the following is a type of crystalline solid? Check all that apply.

metallic ionic covalent network molecular

Which of the following is not a solution?

oil and water

Among molecular solids, which type of substance will result in the highest melting point?

small polar molecules

Solubility is determined by:

solute-solute forces solvent-solvent forces solute-solvent forces

When diluting a solution, which of the following changes? Select all that apply.

solution volume solution concentration liters of solvent

If a supersaturated solution is introduced to a mechanical disturbance or a seed crystal, what will happen?

some solute will precipitate

Molarity is a measure of

the concentration of a solute in a solution. the number of moles of solute dissolved per liter of solution

The attractions in a crystalline solid require ________ to be broken.

the same amount of energy

The attractions in a crystalline solid have:

the same strength

The concentration of a solution formed by dissolving a liquid solute in a liquid solvent each measured in a graduated cylinder, and expressed as a percentage is known as:

the volume percentage

CO(g)+H2(g)+O2(g)⟶CO2(g)+H2O(g) What is ΔH for the reaction above, given the following reaction enthalpies 2C(s)+O2(g)C(s)+O2(g)2H2(g)+O2(g)→2CO(g)→CO2(g)→2H2O(g)ΔH1=−222 kJΔH2=−394 kJΔH3=−484 kJ

−525 kJ