Deck 7: Chemical Reactions How We Keep Track of Chemical Changes

Question 1

The formula for methane is CH₄.3.0 × 10²⁶ molecules of methane would weigh _____ in grams.

Answer 1

8.0 × 10³ g

Question 2

The molar mass for ozone, O₃, is _____; therefore, _____ grams would be contained in 85.0 moles of ozone.

Answer 2

48.0 g/mol; 4080

Question 3

The mass of one third of a mole of carbon is _____.

Answer 3

4.00 g

Question 4

Consider the following balanced chemical equation:
PCl₃ + 3H₂O  H₃PO₃ + 3HCl
If 4.4 moles of PCl₃ react, _____ grams of HCl are formed.

Question 5

How many atoms are there in one molecule of the fatty acid, arachidonic acid, C₂₀H₃₂O₂?

A)32
B)20
C)162
D)54

Question 6

The mass of one mole of calcium is _____.

Question 7

Instead of allowing methane to escape into the atmosphere, where it can contribute to global warming, some farmers are

A)trapping it in underground ponds.
B)collecting it and using it to power their farms.
C)using it as a source of fertilizer on their larger sized fields.
D)combining it with zinc and other nutrients to create feed for animals.

Question 8

The state must always be written in a chemical equation in order for the equation to be considered complete.

Question 9

The law of conservation of mass dictates that there must be the same number of reactant molecules as product molecules.

Question 10

The mass of one mole of phosphorus is _____.

Question 11

Chlorofluorocarbons are present

A)as a natural component of the atmosphere.
B)in aerosol sprays, freezers and refrigerators.
C)as a by-product of the formation of acids in the atmosphere.
D)in sewage effluent that ends up in our rivers and the ocean.

Question 12

The chemical equation shown here is balanced except for the value of x.The value of x is _____.
Ca(ClO₃)₂  CaCl₂ + xO₂

Question 13

Which one of these is not a significant greenhouse gas?

A)carbon dioxide
B)nitrous oxide
C)methane
D)fluorinated gases
E)argon

Question 14

If your car burns 8.0 kg of octane, C₈H₁₈, per month, then it burns _____ moles of octane.

Question 15

The ozone hole

A)can lead to increases in skin cancer rates.
B)has the potential to damage to crops.
C)has formed both in the Arctic and Antarctic.
D)All of the above.

Question 16

The phases on each side of a chemical equation must be the same in order to obey the law of conservation of mass.

Question 17

If a sample of NaCl contains 6.0 moles of NaCl, then the sample contains ____ NaCl molecules.

Question 18

Methane is produced in fairly large quantities by which animal?

A)dogs
B)cows
C)pigs
D)chickens