CHM1020 7-10 Questions
Calculate the mass of 2.10 x 1021 atoms of copper, Cu
0.222 g
A sample of air at 7.50 atm is heated from 250 K to 500 K. If the volume remains constant, what is the final pressure?
15.0 atm
How many formula units of sodium sulfate (Na2SO4) are in 0.333 mol of Na2SO4?
2.00 x 10^23 formula units
A chemical reaction that releases heat energy is said to be
exothermic
What is the mass of copper metal that yields 0.500 g of silver, based on the balanced equation: Cu(s) + 2 AgNO3(aq) -------> Cu(NO3)2(aq) + 2 Ag(s)
0.147 g
In an experiment, 0.243 g of magnesium reacts to give 0.403 g of magnesium oxide. Use the conservation of mass law to predict the mass of reacting oxygen gas 2 Mg(s) + O2(g) ----> 2 MgO(s)
0.160 g
How many moles of water vapor, H2O, react with 1 mol of carbon according to the balanced chemical equation? C(s) + H2O(g) --------> CO(g) + H2(g)
1 mol
What is the coefficient for ammonia (NH3) gas in the following equation? _____ N2(g) + ___H2(g) ------> ___NH3(g)
2
How many xenon atoms are in 10.0 L of Xe gas at STP?
2.69 x 10^23 atoms
The term for the volume occupied by 1 mol of gas at STP is called
molar volume
Calculate the molar mass of aluminum chlorate, Al(ClO3)3.
277.33 g/mol
The pressure of sulfur dioxide at 25oC increases from 0.500 atm to 1.00 atm. What is the final Celsius temperature if the volume remains constant?
323 degrees C
What is the coefficient of water after balancing the following equation? ____H3PO4(aq) + __Ba(OH)2(aq) ----------> ___ Ba3(PO4)2(s) + __H2O(l)
6
Calculate the molar mass of caffeine, C4H5N2O?
97.11 g/mol
Classify the following type of stoichiometry problem: "How many grams of zinc must react with an excess volume of hydrochloric acid to yield 0.500 g of zinc chloride"
mass-mass problem
What volume of hydrogen gas reacts to produce 12.0 mL of ammonia gas, based on the following balanced equation: N2(g) + 3 H2(g) -------> 2 NH3(g)
none of the above
What is the term for the relationship of quantities according to the balanced chemical equation?
stoichiometry
which of the following instruments measures atmospheric pressure?
barometer
The term for a chemical formula that expresses the simplest whole number ratio of atoms of each element in a compound is called
empirical formula
Which of the following is not an observed property of gases?
gases compress infinitely
Which of the following states that pressure and Kelvin temperature are directly proportional for a gas at constant volume?
gay-lussac's law
What principle states that the total mass of products from a chemical reaction must equal to the sum of the masses of the reactants?
law of conservation of mass
Classify the following type of stoichiometry problem: "How many liters of carbon monoxide gas react with an excess volume of oxygen gas to five 125 mL of carbon dioxide gas"
volume-volume problem
The arrow (------->) represents in a chemical equation
yields or produces
The physical state symbol for a solid after a substance is indicated by which of the following?
(s)
A 5.00 L volume of ethane gas is heated from 298 K to 596 K. If the pressure remains constant, what is the final volume?
10.0 L
How many moles of carbon monoxide (CO) react with 1 mol of oxygen gas according to the balanced chemical equation? 2 CO(g) + O2(g)--------> 2 CO2(g)
2 mol
A sample of neon gas at 1.20 atm compresses from 0.250 L to 0.125 L. If the temperature is held constant, what is the final pressure?
2.40 atm
Calculate the number of moles of hydrogen gas produced from 5.00 mol of water, based on the balanced chemical equation: 2 Li(s) + 2 H2O(l) -----> 2 LiOH(aq) + H2(g)
2.50 mol
What is the coefficient for nickel metal after balancing the following equation? ____Fe(s) + __Ni(NO3)2(aq) -------> ____Fe(NO3)3(aq) + ___Ni(s)
3
What is the coefficient for oxygen gas after balancing the following equation? ____P(s) + ___O2(g) -------> ___P2O5(s)
5
Calculate the mass of 2.50 L of sulfur dioxide, SO2, gas at STP.
7.15g
An atmospheric sample is composed of nitrogen, oxygen, argon, and traces of other gases. If the partial pressure of nitrogen is 587 torr, oxygen is 158 torr, and argon is 7 torr, what is the observed barometric pressure?
752 torr
Which of the following gases occupies 22.4 L at STP? a. 1 mol nitrogen, N2 b. 1 mol oxygen. O2 c. 1 mol hydrogen, H2 d. all of the above
all of the above
Which of the following is equal to 1 mol of a substance? a. 6.02 x 1023 sodium atoms, Na b. 6.02 x 1023 lithium fluoride formula units, LiF c. 6.02 x 1023 iodine molecules, I2 d. All of the above
all of the above
Which of the following states that the pressure and volume are inversely proportional for a gas at constant temperature?
boyles law
Which of the following states that the volume and Kelvin temperature are directly proportional for a gas at constant pressure?
charles law
What is the term for the process of undergoing a chemical change?
chemical reaction
What type of chemical reaction is illustrated by the following example? SO2(g) + O2(g) -----> SO3(g)
combination
The type of reaction in which two or more simpler substances are formed from a single compound is called a _____________________ reaction.
decomposition
