Abeka Chemistry 2024 Test 2

What are the correct coefficients for Li2SO4(aq) and H2O in the following reaction? H2SO4(aq) + 2 LiOH(aq) ---> __?__ Li2SO4(aq) + __?__ H2O(I)

1, 2

Write coefficients in the blanks to balance the equation. _____Fe3O4(s) + _____H2(g) --^--> _____H2O(g) + _____Fe(s)

1, 4, 4, 3

If a chemist uses 85.0 g of C6H12 (cyclohexane) for a reaction, how many moles of C6H12 did he use? The molar mass of C6H12 is 84.162 g/mol.

1.01 mol

What is the formula mass of bromine dioxide?

111.902 u

What mass of silver is produced if 15.0 g of silver oxide reacts according to the following equation? 2 Ag2O(s) --^--> 4 Ag(s) + O2(g)

14.0 g Ag

What is the molar mass of ethanol, C2H6O?

46.069 g/mol

What is the value of Avogadro's number?

6.022 X10^23

Match each name with the correct formula: arsenic trifluoride

AsF3

What is the empirical formula of C12H36N4?

C3H9N

The molar mass of lactic acid (a product of anaerobic respiration) is 90.1 g/mol; its percent composition is 40.0%C, 6.7%H, and 53.3%O. What is lactic acid's empirical formula?

CH2O

Match each name with the correct formula: calcium phosphide

Ca3P2

What are the reactants in the following reaction? CaOH(aq) + Na2CO3(s) ---> CaCO3(s) + NaOH (aq)

CaOH, Na2CO3

Delaney has a compound formed of K^+ and S^2- ions. She named this compound potassium sulfide. Is she correct? Why or why not?

Correct; the name is she cation followed by the anion

Match each name with the correct formula: iron(II) fluoride tetrahydrate

FeF2 X 4H2O

If 1.14 mol H2 are mixed with 0.78 mol N2, what is the limiting reactant? How many moles of NH3 can be formed? 3 H2(g) + N2(g) ---> 2 NH3(g)

H2; 0.760 mol

Match each name with the correct formula: ammonium acetate

NH4C2H3O2

Which of the following compounds will be produced by a single-displacement reaction between zinc and copper(II) sulfate? How do you know?

ZnSO4; Zinc replaces copper(II)

What is a hydrate?

a crystalline substance that includes water molecules as part of its structure

What number in a chemical equation is multiplied by every atom in the formula following it?

coefficient

Match each description with the correct term: 2 KCI(s) + 3 O2(g) ---> 2 KCIO3(s)

combination reaction

Match each description with the correct term: AB---> A + B

decomposition reaction

Which of the following tasks can percent composition be used to perform?

determining a compound's empirical formula

What is the name of the binary molecular compound N2O5?

dinitrogen pentaoxide

Match each description with the correct term: AgNO3(aq) + NaCl(aq) ---> AgCl(s) + NaNO3(aq)

double-displacement reaction

Match each description with the correct term: two ionic compounds swap ions

double-displacement reaction

What is the simplest ratio of atoms in a compound?

empirical formula

Be prepared to explain how mole ratios and the law of conservation of mass work. - The reaction still follows the mole ratios. Hydrogen and oxygen will still react in a ratio of 2 mol H2:1 mol O2. The ratio of hydrogen and oxygen that actually reacts to water formed will still be 2 mol H2:2 mol H2O and 1 mol O2:2 mol H2O. Since the initial amounts do not match the mole ratios, one reactant will be a limiting reactant. The other reactant is in excess; some of it will remain unreacted. [H2 is limiting; 1.5mol (27g) of H2O will be formed. The excess O2(2.25mol ~ 2.3mol; 72g) will remain unreacted] - The law of conservation of mass is obeyed in two ways. First, the total mass of H2O produced equals the mass o H2 and O2 that react. Second, the total mass before the reaction (H2 and O2) and the total mass after the reaction (H2O formed and unreacted reactant [O2]) are the same (both 99g).

essay

term-2 Match each formula with the correct name: HCO3^-

hydrogencarbonate

What is the name of the ionic compound Fe2O3?

iron(III) oxide

What law explains why chemical equations must be balanced?

law of conservation of mass

What determines the amount of product that can be formed in a chemical reaction?

limiting reactant

What term refers to Avogadro's number of anything?

mole

In a stoichiometry problem, what provide the link between known and unknown mole amounts of substances?

mole ratios

Match each formula with the correct name: NO2^-

nitrite

Match each formula with the correct name: O2^2-

peroxide

What is the name of the binary molecular compound SeF6?

selenium hexafluoride

What term refers to the numerical relationship between elements and compounds in a reaction?

stoichiometry

Match each formula with the correct name: SO4^2-

sulfate