Question

Chem help! Fan and points

Answer 1

8) ( 1 point) What is the maximum number of grams PH₃ that can be formed when 3.4 g of phosphorus reacts with 4 grams of hydrogen to form PH₃? P₄ (g) +6H₂ (g) → 4PH₃ (g) *
3.7 g
6.8 g
45 g
270 g

9) ( 1 point) Which of the following is NOT true about percent yield? *
Percent yield is often less than 100%
Percent yield measures the efficiency of a reaction carried out in a lab.
Percent yield of 100% is unlikely when reactants or products were not carefully measured.
Percent yield is the ratio of theoretical yield to actual yield expressed as a percent.

10) ( 1 point) Lead nitrate can be decomposed by heating. What is the percent yield of the decomposition reaction if 15.6 g Pb(NO₃)₂ are heated to give 9.4 g of PbO? 2Pb(NO₃)₂ (s) → 2PbO(s) +4NO₂(g) + O₂(g) *
59%
73%
82%
90%