Intro to Chemistry

Lithium reacts with nitrogen to make lithium nitride. Which of the following reaction equations is balanced correctly?

6Li + N2 → 2Li3N

Give the exact spelling of the name of the compound with formula CaS. (remember element names are not proper nouns, they are not capitalized)

calcium sulfide

What is an electrolyte?

Any substance whose aqueous solution contains ions.

What is the molecular formula for styrene, which has formula mass of 104 g/mol, and the following percent composition by mass: C = 92.3% H = 7.7%

C8H8

What is the empirical formula of a substance that has the following percent composition by mass. C = 10.4% S = 27.8% Cl = 61.7%

CSCl2

Determine the formula mass for nitrogen pentoxide, N2O5.

108 g/mol

What is the mass of 0.773 mol of calcium hydride, CaH2 ?

32.5 g

How many moles of chloride ions are in 0.2550 g of aluminum chloride, AlCl3 ?

5.737 x 10-3 mol

Benzene reacts with bromine to make bromobenzene and hydrogen bromide. C6H6 + Br2 → C6H5Br + HBr What is the theoretical yield for this reaction when 30.0g of benzene reacts with 65.0g of bromine?

60.3 g

Which reaction equation displays all the dissolved electrolytes as ions?

Complete ionic equation.

What is molarity?

The number of dissolved moles of substance in a liter of solvent.

What is a titration?

The reaction of a known quantity of a solution of one substance with an unknown quantity of another substance.

Which scientific principle is used when balancing chemical equations?

The law of conservation mass.

What is oxidation?

loss of electrons.

Give the exact spelling of the name of the element with symbol Mg. (remember element names are not proper nouns, they are not capitalized)

magnesium

Give the exact spelling of the name of the element with symbol P. (remember element names are not proper nouns, they are not capitalized)

phosphorus

Give the exact spelling of the name of the element with symbol Na. (remember element names are not proper nouns, they are not capitalized)

sodium