A person forms 8.79mol of C4H10 according to the reaction below. How much energy, in kilojoules, was released? (Use a negative number if energy is released and a positive number if energy is added.) (Round to 2 Decimal Places) AH°= 4C (s) + 5H2 (g) → C4H10 (g) - 125.6 kJ/mol​

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

3) in peaches, [oh]=3.16x10-11 m a) find [h+ ] b) what is the ph? c) is the solution acidic, basic, or neutral?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)