Moles and Reactions Chemistry 4 Exam

In the reaction CH4 + 2 O2 → CO2 + 2 H2O, how many moles of oxygen are required to burn 8.0 g of methane? A) 0.5 B) 1.0 C) 2.0 D) 32

B) 1.0

How many moles of (NH4)2S are there in 75 g of (NH4 )2S? A) 1.04 B) 1.10 C) 1.50 D) 1.56

B) 1.10

Aspirin has a formula C9H8O4. The molar mass of aspirin is A) 95 g/mole. B) 180 g/mole. C) 220 g/mole. D) 325 g/mole

B) 180 g/mole.

Nitroglycerin has a formula C3H5 (NO3 )3 . The molar mass of nitroglycerin is A) 65 g/mole. B) 227 g/mole. C) 309 g/mole. D) 398 g/mole.

B) 227 g/mole.

Which of the following contains Avogadro's number of atoms? A) 15.5 g of phosphorus B) 39 g of potassium C) 40 g of bromine D) 100 g of mercury

B) 39 g of potassium

The total number of each type of atom must be the same on both sides of an equation in order to satisfy the A) Law of Combining Volumes. B) Law of Conservation of Matter. C) Law of Constant Composition. D) Law of Multiple Proportions.

B) Law of Conservation of Matter.

Which of the following contains as many atoms as 18 g of water, H2O? A) one mole of nitrogen, N2 B) three moles of zinc, Zn C) two moles of sodium chloride, NaCl D) two moles of nitrogen, N2

B) three moles of zinc, Zn

Avogadro's number is

6.02 × 10^23

Calcium metal reacts with water to form calcium hydroxide and hydrogen gas. How many grams of hydrogen are formed when 0.50 g of calcium are added to water? A) 0.025 g B) 0.050 g C) 0.10 g D) 0.50 g

A) 0.025 g

Joseph Priestley discovered oxygen in 1774 by heating mercury(II) oxide. The compound decomposes into its elements. How much oxygen, O2, is produced by the decomposition of 25 g of HgO? A) 1.8 g B) 3.7 g C) 5.5 g D) none of these

A) 1.8 g

What is the mass of 0.500 mol of NH3? A) 8.50 g B) 3.40 g C) 7.50 g D) 34.0 g

A) 8.50 g

Which of the following has the same number of atoms as 35.4 g of chlorine? A) 35.4 g of germanium B) 19 g of potassium C) 12 g of carbon D) 18 g of water

C) 12 g of carbon

Acetylene (C2H2) burns in pure oxygen with a very hot flame. The products of this reaction are carbon dioxide and water. How much oxygen is required to react with 52.0 g of acetylene? A) 32.0 g B) 52.0 g C) 160. g D) 240. g

C) 160. g

In the reaction CH4 + 2 O2 → CO2 + 2 H2O, how many moles of oxygen are required to burn 16.0 g of methane? A) 0.500 B) 1.00 C) 2.00 D) 32.0

C) 2.00

Consider the following equation: N2 + 3 H2 → 2 NH3 Which of the following statements is NOT true for this equation? A) 3 mole of N2 reacts with 9 moles of H2. B) 1 L of N2 reacts with 3 L of H2. C) 3 gram of N2 reacts with 9 grams of H2. D) 2 molecule of N2 reacts with 6 molecules of H2.

C) 3 gram of N2 reacts with 9 grams of H2.

What is the molar mass of N2O? A) 30 g/mole B) 30 u C) 44 g/mole D) 44 u

C) 44 g/mole

How many moles of sulfur atoms are present in 4.00 moles of CS2 A) 2.00 B) 4.00 C) 8.00 D) 12.00

C) 8.00

Which of the following does NOT contain Avogadro's number of particles? A) 1.0 mole of silver B) 23 g of sodium C) 6.02 × 1023 atoms of aluminum D) 12 g of water

D) 12 g of water

What is the molecular mass of N2O? A) 30 g/mole B) 30 u C) 44 g/mole D) 44 u

D) 44 u

The formula mass of CO2 is A) 28 g/mole. B) 28 u. C) 44 g/mole. D) 44 u.

D) 44 u.

How many molecules are in 237 g (about a cup) of water? A) 13.1 B) 4267 C) 6.02 × 10^23 D) 7.92 × 10^24

D) 7.92 × 10^24