Chem
Enter the chemical formula from the given name here. ammonium sulfite
(NH4)2SO3
The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas, assuming no change in moles or temperature?
.30
The number 5.820 x 10-4 converted to normal (decimal) notation is: 0.00582 0.5820 582,000 0.0005820 5820
0.0005820
What is the correct answer for the following calculation, reported using the proper number of significant figures: 12.4 / 775.5 =
0.0160
A balloon that contains 0.500 L of helium at 25 °C is cooled to 11 °C, at a constant pressure. What volume does the balloon now occupy? Include the correct units.
0.477 L
What is the mass of neon that exerts a pressure of 720. mmHg,with a temperature of -15.0 °C , when the volume of the container is 760. mL?
0.686 g
Na+ has 11 protons and ___ total electrons.
10
How many valence electrons are in a molecule of acetylene (C2H2)? Draw the Lewis structure of acetylene: how many bonds will exist in between the two carbon atoms?
10, 3
A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in mmHg?
1140 mmHg
What is the molarity of a solution that contains 3.25 moles of NaNO3 in 250. mL of solution?
13.0 M
What is the maximum number of grams of NO (30.01 g/mol) that can be formed from the reaciton of 16.5 g of NH3 (17.03 g/mol) with 20.5 g of O2 (32.00 g/mol)? 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(l)
15.4
What mass of oxygen will react with 17.5 g of aluminum according to the following reaction? 4 Al + 3 O2 → 2 Al2O3
15.6
A calculator answer of 1723.6059 must be rounded off to two significant figures. What answer is reported?
1700
What is the electron configuration of the F- ion?
1s2 2s2 2p6
How many moles of gas are there in a gas-filled balloon, which has a volume of 67.0 L at a pressure of 742 mmHg and a temperature of 25.0°C?
2.67 moles
A calculator answer of 24.059 must be rounded off to three significant figures. What answer is reported?
24.1
How many moles of water (H2O) can be produced from 4.2 moles of O2 and an excess amount of C6H14? 2 C6H14 (l) + 19 O2 (g) --> 12 CO2 (g) + 14 H2O (g)
3.1
A runner is running a 10 K charity race (consider the distance as 10.00 Km from a significant figures in calculations point of view.) After 20 minutes a timecheck is done and it shows that 3.75 miles have been ran in the first 20 minutes. How many Km are left for the runner now?
3.96
Which of the following numbers is the largest? 4.0 × 10-8 4.0 × 10-2 4.0 × 10^15 4.0 × 10-6 4.0 × 10-12
4.0 × 10^15
If a package of nuts weighs 1.17 x 106 mg, what is the mass of package reported in ounces?
41.3
How many moles of water, H2O, are present in 90.9 g of H2O?
5.05
A calculator answer of 520.0332 must be rounded off to four significant figures. What answer is reported?
520.0
What is the correct answer to this calculation, reported using the proper number of significant figures: 755.101 + 4.73 + 5.0076 - 700.4 =
64.4
A calculator answer of 71.03954 must be rounded off to one significant figures. What answer is reported?
70
What is the percent yield for a reaction in which 24.6g of a product is actually produced when the theoretical yield is 30.0g?
82
What is the mass in grams of 82.94 mL of blood plasma with a density of 1.01 g/mL? Here the units are understood to be grams (g), so just enter the numeric answer to the question.
83.8
The breaking of a bond: A. This process requires energy. B. This process releases energy. The making of a new bond: A. This process releases energy. B. This process requires energy.
A B
A value of 225 K is a measurement of [x] on the [y] scale. distance density mass temperature metric S.I.
A value of 225 K is a measurement of temperature on the S.I. scale.
How many moles of CO2 are consumed when 11.0g of NH3 react completely in the following equation? CO2 + 2NH3 -> CO(NH2)2 + H2O A. 0.324 B. 1.55 C. 0.646 D. 0.387
A. 0.324
All of the following contain the same number of molecules except A. 32.0g of oxygen molecules B. 1.20 X 1024 molecules of water C. 36.04g of water molecules D. 141.8g of chlorine molecules
A. 32.0g of oxygen molecules
When 60.0 g of CH4 reacts with excess O2, the actual yield of CO2 is 112 g. What is the percent yield? CH4 + 2O2 → CO2 + 2H2O A. 67.9% B. 46.4% C. 18.7% D. 53.6%
A. 67.9%
2KClO3 -> 2KCl + 3O2. How many moles of O2 are produced when 6.0 moles of KCl are produced? A. 9.0 B. 3.0 C. 4.0 D. 6.0
A. 9.0
A hydrogen bond is an attraction between a hydrogen atom attached to N, O, or F and a(n) ______ atom on another molecule. A. F B. O C. N D. C E. S F. H G. Cl
A. F B. O C. N
Click on all the following statements that describe an exothermic reaction. A. Heat is released. B. N2 + O2 + heat --> 2NO C. N2 + 3H2 --> 2NH3 + 22 kcal D. The products are lower in energy than the reactants E. The bonds formed in the products are stronger than the bonds broken in the reactants. F. The bonds broken in the reactants are stronger than the bonds made in the products. G. Heat is absorbed. H. The sign on the enthalpy change for the reaction is positive.
A. Heat is released. C. N2 + 3H2 --> 2NH3 + 22 kcal D. The products are lower in energy than the reactants E. The bonds formed in the products are stronger than the bonds broken in the reactants.
What are all the factors that increase the rate of a reaction? A. The concentration of the reactants. B. The presence of a catalyst. C. The temperature of the reaction. D. The enthalpy change for the reaction. E. The surface area of the reactant - if it is a solid. F. The molar mass of the reactants.
A. The concentration of the reactants. B. The presence of a catalyst. C. The temperature of the reaction. E. The surface area of the reactant - if it is a solid.
The boiling point of water at sea level is 100 °C. At higher altitudes, the boiling point of water will be A. lower, because the atmospheric pressure is lower. B. the same, because water always boils at 100 °C. C. lower, because temperatures are lower. D. higher, because the altitude is greater. E. higher, because there are fewer water molecules in the air.
A. lower, because the atmospheric pressure is lower.
In an atom, the nucleus contains: A. protons B. neutrons C. positrons D. electrons E. negatively charged subatomic particles
A. protons B. neutrons
An equilibrium constant with a value of 1.5 × 10-9 indicates that at equilibrium A. the reactants are favored. B. the products are favored. C. approximately equal concentrations of both reactant and products.
A. the reactants are favored.
Enter the systematic name for the following substance. NH4Cl
Ammonium Chloride
How many moles are contained in 5.33 L of O2 at standard temperature and pressure? A. 22.4 moles B. 0.238 moles C. 1.00 moles D. 5.33 moles
B. 0.238 moles
What is the molar mass of glycine shown here? A. 63.08 g/mol B. 75.09 g/mol C. 74.082 g/mol D. 59.09 g/mol
B. 75.09 g/mol
Which of the following substances contains a nonpolar covalent bond? A. H2O B. N2 C. C2H6 D. Br2 E. NaCl F. CH4 G. NH3 H. MgF2
B. N2 C. C2H6 D. Br2 F. CH4
When 85.0 g of CH4 are mixed with 160. g of O2 the limiting reactant is CH4 + 2O2 → CO2 + 2H2O A. H2O B. O2 C. CO2 D. CH4
B. O2
Which one of the following properties describes a solid? A. particles are close together and move randomly B. There are strong interactions between the particles. C. has an indefinite shape D. particles move very rapidly E. fills the entire volume of the container
B. There are strong interactions between the particles.
Enter the chemical formula from the given name here. boron trifluoride
BF3
Enter the systematic name for the following substance. Ba(OH)2
Barium Hydroxide
A cyclopropane-oxygen mixture is used as an anesthetic. If the partial pressure of cyclopropane in the mixture is 330 mmHg and the partial pressure of the oxygen is 1.0 atm, what is the total pressure of the mixture in torr? A. 760 torr B. 430 torr C. 1100 torr D. 1.4 torr E. 330 torr
C. 1100 torr
What volume would a 0.250 mole sample of H2 gas occupy, if it had a which has a pressure of 1.70 atm, and a temperature of 35 °C? A. 0.269 L B. 1.25 L C. 3.72 L D. 0.423 L E. 283 L
C. 3.72 L
Consider the reaction, 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g) + 137 kJ. How many kilojoules are released when 95.7 g of NO2 reacts? A. 2.08 kJ are released B. 13100 kJ are released C. 95.0 kJ are released D. 285 kJ are released
C. 95.0 kJ are released
What is the correct order of the steps in the scientific method? A. Ask a question, analyze results, make a hypothesis, test the hypothesis, draw conclusions, communicate results. B. Make a hypothesis, test the hypothesis, analyze the results, ask a question, draw conclusions, communicate results. C. Ask questions, make a hypothesis, test the hypothesis, analyze results, draw conclusions, communicate results. D. Ask a question, make a hypothesis, test hypothesis, draw conclusions, analyze results, communicate results.
C. Ask questions, make a hypothesis, test the hypothesis, analyze results, draw conclusions, communicate results.
Which chemical formula is correct? A. AgCl2 B. K2CN C. Mg(OH)2 D. MgNO3 E. More than one of the above formulae are correct.
C. Mg(OH)2
With regard to the Group 7A(17) elements, select the incorrect statement: A. They are known as the halogens. B. They have 7 valence electrons. C. They are metallic in nature. D. They may be solids, liquids or gases. E. They are highly reactive and are invariably found in combination with other elements.
C. They are metallic in nature.
In a molecule with covalent bonding A. atoms of metals form bonds to atoms of nonmetals. B. atoms of different metals form bonds. C. atoms are held together by sharing electrons. D. atoms of noble gases are held together by attractions between oppositely charged ions. E. oppositely charged ions are held together by strong electrical attractions.
C. atoms are held together by sharing electrons.
Which of the following elements will occur as diatomic molecules? A. sulfur B. carbon C. chlorine D. hydrogen E. helium F. phosphorus G. iodine H. oxygen I. nitrogen J. selenium K. fluorine L. bromine
C. chlorine D. hydrogen G. iodine H. oxygen I. nitrogen K. fluorine L. bromine
The mass number of an atom is equal to the number of A. nuclei. B. neutrons. C. neutrons plus protons. D. protons. E. electrons plus protons.
C. neutrons plus protons.
Oil does not dissolve in water because A. oil is less dense. B. water is nonpolar C. oil is nonpolar. D. oil is hydrated. E. water is saturated. F. oil is polar.
C. oil is nonpolar.
Enter the chemical formula from the given name here. methane
CH4
Select all the gases in the following list. Al CO ammonia carbon dioxide hydrogen Argon carbon iodine He NO2 lithium Oxygen Mg selenium F2 C6H14 CH4 N2 chlorine Na
CO ammonia carbon dioxide hydrogen He NO2 Oxygen F2 N2 chlorine
Enter the systematic name for the following substance. CaCO3
Calcium Carbonate
At STP, what is the mass of 11.2 liters of O2 gas? A. 8.00 g B. 32.0 g C. 64.0 g D. 16.0 g E. 128 g
D. 16.0 g
What is the molarity of a solution, which contains 58.5 g of sodium chloride dissolved in 0.500 L of solution? A. 0.500 M B. 4.00 M C. 1.00 M D. 2.00 M E. 1.50 M
D. 2.00 M
What is the molar mass of Mg3(PO4)2? A. 214 g B. 150. g C. 118 g D. 263 g E. 71.3 g
D. 263 g
How many atoms of neon are present in 1.30 moles of neon? A. 4.63 × 1023 atoms B. 7.83 × 1022 atoms C. 6.02 × 1023 atoms D. 7.83 × 1023 atoms
D. 7.83 × 1023 atoms
Which phase change absorbs energy? A. Fe (l) -> Fe (s) B. H2O (l) -> H2O (s) C. H2O (g) -> H2O (l) D. CH3OH (l) -> CH3OH (g)
D. CH3OH (l) -> CH3OH (g)
After rearrangement of the combined gas law what is the correct expression to solve for V2? A. V2 = T2 T1 V1/P2P1 B. V2 = P2T2/P2V1T1 C. V2 = P1V1/T1 - P2/T2 D. V2 = P1V1T2/P2T1 E. V2 = P1V1T1/P2T2
D. V2 = P1V1T2/P2T1
Consider the reaction: N2(g) + O2(g) -> 2 NO(g). This is a reversible reaction. At equilibrium, removing some of the N2(g) will _____. A. decrease the concentration of O2(g) B. increase the concentration of NO(g) C. More than one of the above answers is correct. D. increase the concentration of O2(g)
D. increase the concentration of O2(g)
For an endothermic reaction, increasing the temperature A. increases the rate of the reverse reaction to form more products. B. increases the rate of the reverse reaction to form more reactants C. does not shift the equilibrium since K is a constant. D. increases the rate of the forward reaction to form more products
D. increases the rate of the forward reaction to form more products
The shape of the carbon dioxide (CO2) molecule is A. trigonal pyramidal B. bent C. trigonal planar D. linear
D. linear
A chemical equation is balanced when A. the total number of ions is the same in reactants and products. B. the sum of the coefficients of the reactants and the products are equal. C. the total number of molecules is the same in reactants and products. D. the number of atoms of each element is the same in reactants and products. E. the charge on each atom is the same in reactants and products.
D. the number of atoms of each element is the same in reactants and products.
Isotopes are atoms of the same element that have A. the same atomic numbers but different numbers of electrons. B. the same atomic numbers but different numbers of protons. C. the same atomic mass but different numbers of protons. D. the same atomic numbers but different numbers of neutrons. E. different atomic numbers.
D. the same atomic numbers but different numbers of neutrons.
How many moles of N2 will be consumed when 1.60 moles of H2 react completely in the following equation? N2 + 3H2 -> 2NH3 A. 3.20 B. 4.80 C. 1.07 D. 1.60 E. 0.533
E. 0.533
The total pressure in a mixture of gases is equal to the partial pressure(s) of A. the gas with the highest molecular weight. B. the gas with the smallest number of moles. C. the gas that occupies the largest volume. D. the gas with the greatest number of moles. E. all the gases added together.
E. all the gases added together.
An increase in the temperature of a solution usually A. increases the solubility of a gas in the solution. B. decreases the solubility of a solid solute in the solution. C. decreases the solubility of a liquid solute in the solution. D. increases the boiling point. E. increases the solubility of a solid solute in the solution.
E. increases the solubility of a solid solute in the solution.
The number of valence electrons found in an atom of a Group A (main group) element is equal to ... A. it's atomic number. B. eight minus the group number. C. eight. D. it's mass number. E. it's group number
E. it's group number
In the kinetic molecular theory of gas behavior, the assumption is made that gas molecules A. are attracted to each other by strong forces. B. decrease kinetic energy as temperature increases. C. are close together in their container. D. occasionally come to rest. E. move rapidly in random directions.
E. move rapidly in random directions.
Enter the systematic name for the following substance. FeBr2
Iron (II) Bromide
Enter the chemical formula from the given name here. potassium fluoride
KF
Which of the following describes an oxidation reaction? Loss of hydrogen Gain of electrons Loss of oxygen Loss of electrons Gain of oxygen
Loss of hydrogen, Loss of electrons, and Gain of oxygen
Enter the systematic name for the following substance. MgO
Magnesium Oxide
Enter the systematic name for the following substance. OF2
Oxygen Difluoride
The following reaction takes place when an electric current is passed through water. It is an example of a ________ type of reaction. 2H2O → 2H2 + O2
decomposition
Enter the systematic name for the following substance. I2O5
diiodine pentoxide
Which of the states of matter is highly compressible?
gas
Which state of matter has particles with the greatest kinetic energy?
gas
The Greek letter delta (Δ) may be written over the reaction arrow in a chemical equation to indicate that [x] is needed for the reaction to occur. water a catalyst heat an oxidizing agent
heat
A pure substance at atmospheric pressure when the temperature is in between it's melting and boiling points will be which state of matter?
liquid
Enter the systematic name for the following substance. NaNO3
sodium nitrate
Which state of matter is composed of particles that vibrate in a fixed position?
solid
STP is defined as a pressure of exactly [X] and a temperature of [Y]. 760 atm 1 atm 1 mmHg 760 psi 1 K 1 deg.C 273 K 100 deg.C
x-1 atm y-273 K
What does one mole of helium gas weigh to three significant figures? [x] What does one mole of oxygen gas weigh to three significant figures? [y]
x-4.00 y-32.0
The phrase "ability to do work" is a definition of [x] and its units are [y] or [z]. energy joules calories
x-energy y-joules z-calories