7.50 L of a gas is collected at 70.0 °C. What will be its
volume upon cooling to 25.0 °C?

Which of the following best explains why the end of a spoon sticking out of a cup of hot water also gets hot? question 7 options: the heat from the hot water is conducted through the spoon handle the hot water heats the air surrounding the upper part of the spoon. the hot water causes a physical change in the spoon handle. the hot water causes a chemical reaction to take place in the spoon.

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.)

What type of reaction fuels the processes seen here?