Answer !
a serving of drinking water( h2o )has an approximate mass of 255 g. water has a specific heat capacity (csp) of 4.184 j/g×°c. what is the total energy needed to heat 255-grams of water from 20.0°c to 100.0°c?

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 is the percentage of hydrogen in nitrogen trihydride

What are the major types of a chemical compound