Chem 7

Avogadro's number is the number of ________. Select one: a. moles in 6.02 × 10^23 g of an element b. particles in 1 mole of a substance c. moles in 6.02 × 10^23 amu of an element d. grams in 1 mole of a substance e. amu in 1 mole of a substance

How many moles of water, H2O are present in 75.0 g H2O? Select one: a. 4.41 moles b. 75.0 moles c. 4.16 moles d. 1.35 × 10^3 moles e. 7.50 moles

0.100 mole of lithium has a mass of ________. Select one: a. 0.700 g b. 6.94 g c. 0.694 g d. 3.00 g e. 0.300 g

4.00 moles of sodium have a mass of ________. Select one: a. 92.0 g b. 23.0 g c. 11.0 g d. 44.0 g e. 4.60 g

3.00 moles of NO2 have a mass of ________. Select one: a. 45.0 g b. 138 g c. 30.0 g d. 90.0 g e. 46.0 g

How many grams of Fe2O3 are there in 0.500 mole of Fe2O3? Select one: a. 35.9 g b. 63.8 g c. 160. g d. 79.9 g e. 51.9 g

A chemical equation is balanced when ________. Select one: a. the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products b. the total number of ions is the same in reactants and products c. the charge on each atom is the same in reactants and products d. the total number of molecules is the same in reactants and products e. the number of atoms of each element is the same in reactants and products

In any balanced chemical equation, the number of each type of atom on both sides of the equation is ________. Select one: a. dependent on the temperature b. decreased by one c. the same d. doubled e. increased by one

What is oxidized and what is reduced in the following reaction: 2Al + 3Br2 → 2 AlBr3? Select one: a. AlBr3 is reduced and Br2 is oxidized. b. Al is reduced and Br2 is oxidized. c. Al is oxidized and Br2 is reduced. d. AlBr3 is oxidized and Al is reduced. e. AlBr3 is reduced and Al is oxidized

In an oxidation-reduction reaction, the substance oxidized always ________. Select one: a. loses electrons b. becomes a charged species c. takes on oxygen atoms d. gives up hydrogen atoms e. gains electrons

In this reaction, what is the substance oxidized: Zn + 2 HCl → ZnCl2 + H2? Select one: a. oxygen b. zinc c. chlorine d. zinc chloride e. hydrogen

One mole of copper (II) sulfate, CuSO4, contains ________ moles of O. Select one: a. 2.41 × 10^23 b. 2.41 × 10^24 c. 4 d. 1.51 × 10^23 e. 6.02 × 10^23

In an oxidation-reduction reaction, the substance reduced always ________. Select one: a. loses electrons b. gains electrons c. becomes a charged species d. takes on oxygen atoms e. gives up hydrogen atoms

The ________ is the minimum energy needed for a chemical reaction to begin. Select one: a. energy of reactants b. heat of reaction c. reaction energy d. energy of products e. activation energy

A reaction that releases energy as it occurs is classified as a(n) ________. Select one: a. decomposition reaction b. oxidation-reduction reaction c. catalyzed reaction d. exothermic reaction e. endothermic reaction

What type of reaction is: CH4 + 2O2 → CO2 + 2H20 + 218 KCal? Select one: a. a decomposition reaction b. an endothermic reaction c. an exothermic reaction d. a combination reaction e. a single replacement reaction

If the following reaction is exothermic, H2 + O2 → 2H2O the energy level of the reactants is ________. Select one: a. possibly lower, possibly higher than that of the products b. higher than that of the products c. lower than that of the products d. the same as that of the products e. higher than the activation energy of the reaction

Any reaction that absorbs 150 kcal of energy can be classified as ________. Select one: a. endothermic b. reduction c. activated d. oxidation e. exothermic

The ________ is the energy difference between reactants and products in a chemical reaction. Select one: a. product energy b. transition energy c. activation energy d. overall energy e. heat of reaction

0.400 mole of sucrose, C12H22O11 contains ________ moles of C. Select one: a. 2.89 × 10^24 b. 12 c. 6.02 × 10^23 d. 4.80 e. 5.02 × 10^22

How many moles of carbon atoms are there in 0.500 mole of C2H6? Select one: a. 4.00 moles b. 3.00 moles c. 0.500 mole d. 1.00 mole e. 6.02 × 10^23 moles

The molar mass of potassium is ________. Select one: a. 39.10 g/mole b. 19.00 g/mole c. 6.02× 10^23 g/mole d. 15.02 g/mole e. 31.00 g/mole

The molar mass of helium is ________. Select one: a. 4.003 g b. 3.003 g c. 1.000 g d. 2.002 g e. 8.006 g

Calculate the molar mass of potassium chloride, KCl. Select one: a. 6.745 g/mole b. 74.55 g/mole c. 19.00 g/mole d. 67.45 g/mole e. 54.55 g/mole

The molar mass of C3H8O2 is ________. Select one: a. 76.09 g/mole b. 60.09 g/mole c. 69.02 g/mole d. 52.01 g/mole e. 29.02 g/mole

What is the molar mass of Mg3(PO4)2 a substance formerly used in medicine as an antacid? Select one: a. 150.3 g/mole b. 262.9 g/mole c. 214.3 g/mole d. 118.3 g/mole e. 71.28 g/mole