A. 2 H2 + O2 → 2 H2O
B. 4 H2 + 2 O2 → 4 H2O
C. Both A and B
D. None of the above
1-31-2. Which of the following is the balanced chemical equation for the following reaction: Mg + O2 → MgO
A. Mg + O → MgO
B. Mg + O2 → MgO + O
C. Mg2 + O2 → 2 MgO
D. 2 Mg + O2 → 2 MgO
1-31-3. Consider the following chemical equation where coefficients are represented by the letters w,x,y, and z:
w Al2O3 + x H2SO4 → y Al2(SO4)3 + z H2O
If w=1, then which of these is true?
A. y=2, B. z=3, C. x=6
1-31-4. Consider the combustion of propane: C3H8 + O2 → CO2 + H2O(unbalanced)Using the smallest set of whole numbers, the sum of the coefficients in the balanced chemical equation is:
A. 7, B. 9, C. 12, D. 13
1-31-5. Consider the pictorial representation of a chemical change shown below. Using the smallest set of whole numbers, the coefficient of C2H2 in the balanced chemical equation for this reaction is...
A. 1, B. 2, C. 3, D. 4
1-31-6. Consider the pictorial representation of a chemical change shown below. Using the smallest set of whole numbers, the coefficient of NH3 in the balanced chemical equation for this reaction is...
A. 2, B. 3, C. 4, D. 6
1-31-7. Consider the following observations of a chemical change: A small amount of orange-red solid is heated in a test tube. A little explosion occurred and a green powder was obtained. The mass of the green solid was found to be less than that of the original orange-red solid. Which of the following chemical equations is consistent with the observations above?
A. Mg(s) + O2(g) → 2 MgO(s)
B.(NH4)2Cr2O7(s) → 2 N2(g) + Cr2O3(s) + 4 H2O(g)
C. 2 HgO(s) → 2 Hg(l) + O2(g)
D. Pb(NO3)2(aq) + 2 NaCl(aq) → PbCl2(s) + 2 NaNO3(aq)
