Ms. Abernathy's Chemistry Chapter 7 and 8 test

Which coefficients correctly balance the formula equation below? KClO3(s)→ KCl(s) + O2(g)

• 1,1,1

• 2,2,3

• 1,1,3

• 2,1,1

Calcium carbonate, CaCO3, reacts to form calcium oxide, CaO, and carbon dioxide, CO2. What type of reaction is this?

• synthesis

• decomposition

• replacement

• combustion

A formula that shows the simplest whole-number ratio of the atoms in a compound is the

• Molecular formula.

• Ideal formula.

• Experimental formula.

• Empirical formula.

The equation AX + BY → AY + BX is the general equation for a

• Synthesis reaction

• Decomposition reaction

• Single-displacement reaction

• Double-displacement reaction

To balance a chemical equation, you must

• adjust the coefficients.

• adjust the number of products.

• adjust the number of reactants.

• adjust the subscripts.

The molar mass of MgI2 is

• the sum of the masses of 1 mol of Mg and 2 mol of I

• the sum of the masses of 1 mol of Mg and 1 mol of I

• the sum of the masses of 1 atom of Mg and 2 atoms of I

• the sum of the masses of 1 atom of Mg and 1 atom of I

What type of chemical reaction does the following chemical equation represent? 2HCl(aq) + Cr(s) → H2(g) + CrCl2(aq)

• composition

• single-displacement

• decomposition

• double-displacement

The empirical formula for a compound shows the symbols of the elements with subscripts indicating the

• Actual numbers of atoms in a molecule.

• Number of moles of the compound in 100 g.

• Smallest whole-number ratio of the atoms.

• Atomic masses of each element.

Which of the following equations represents the balanced equation for the reaction of iron and oxygen?

• 2Fe + O2 → Fe2O3

• Fe + 3O2 → Fe2O3

• 4Fe + 3O2 →2Fe2O3

• 3Fe + 3O2 → 2Fe2O3

What is the formula mass of magnesium chloride, MgCl2?

• 46 amu

• 95.21 amu

• 59.76 amu

• 106.35 amu