CHE 101-Ch 4 Quiz

Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

2O2 (possibly (O2)2)

Which symbol, often found in chemical equations, indicates that a substance is dissolved in water?

(aq)

The chemical equation below is unbalanced. What is the coefficient of water when the equation is balanced?

Mg(OH)2(s) + HCl(g) → MgCl2(s) + H2O(l)

2

Consider the chemical equation shown below. How many moles of oxygen gas are needed to react with hydrogen to form one mole of water?

2H2(g) + O2(g) → 2H2O(l)

0.5 mol

Glucose (C6H12O6) is an important energy-rich compound, produced by photosynthesis according to the equation below. What mass of glucose can be produced from 2.61 mol of CO2 and the necessary water? [Molar masses: C, 12.01 g/mol; H, 1.01 g/mol; O, 16.00 g/mol]

6CO2(g) + 6H2O(l) → C6H12O6(l) + 6O2(g)

78.4 g

What are the formulas for the products that are expected in the double-replacement reaction shown below?

FeSO4(aq) + NaOH(aq) →

Fe(OH)2 and Na2SO4

How is the reaction shown below best classified?

Ca(s) + 2HCl(aq) → CaCl2(g) + H2(g)

single-replacement

How is the reaction shown below best classified?

2HgO(s) → 2Hg(l) + O2(g)

decomposition

Cis-platin is a chlorine-containing chemotherapy agent with the formula Pt(NH3)2Cl2. What is the mass of one mole of cis-platin?

300.06 g/mol

Dinitrogen monoxide, or laughing gas (N2O), is used as a dental anesthetic and as an aerosol propellant. How many molecules of N2O are present in a 12.6 g sample of the compound?

1.72 x 1023 molecules

When the equation below is balanced with the lowest possible whole number coefficients, what is the sum of the coefficients?

Ca(s) + HCl(g) → CaCl2(s) + H2(g)

2 (WRONG) IT'S FIVE, LEARN TO FREAKING ADD!!!!!!!!!

What mass of sodium hydroxide is necessary to react with a solution containing 73.00 g HCl, according to the chemical equation below? [Molar masses: NaOH, 39.99 g/mol; HCl, 36.45 g/mol]

NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

80.09 g

How many atoms of sulfur are present in a 155 g sample of sulfur? [Molar mass: S, 32.06 g/mol]

2.91 x 1024 atoms

Which of the choices is the correctly balanced form of the following equation?

Fe(s) + O2(g) → Fe2O3(s)

4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)

Classify the following reaction:

Cl2(g) + 2 Fe2+(aq) → 2 Cl-(aq) + 2 Fe3+(aq)

oxidation - reduction

Select the ionic compound which is insoluble in water.

Ni(OH)2

Iron reacts with oxygen to form iron(III) oxide according to the chemical equation below. What is the theoretical yield of product when 5.00 grams of Fe react with excess O2? [Molar masses: Fe, 55.85 g/mol; O, 16.00g/mol]

4Fe(s) + 3O2(g) → 2Fe2O3(s)

7.15 g