To use the gas law constant R = 0.0821, the unit for temperature should be Kelvin and the unit for volume should be milliliters.

true or false

To save time, you can approximate the initial mass of the solid to the nearest ±1 g. for example, if you are asked to add 14.3 g of copper, add between 13 g and 15 g. which of the following sets include two samples with an equal density? which all that apply below 15.4 g gold and 18.7 g silver 15.2 g copper and 50.0 g copper 20.2 g silver and 20.2 g copper 11.2 g gold and 14.9 g gold

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

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.)