Chemistry, 30.04.2021 16:50 avrieell8584
A science teacher places a sealed microwave bag of popcorn on a balance and measures its mass.
She microwaves the popcorn and finds the mass again before opening the bag. The masses are nearly the same.
Which scientific law does this BEST demonstrate?
Law of Conservation of Energy
Law of Thermodynamics
Law of Conservation of Volume
Law of Conservation of Matter
Answers: 2
Chemistry, 22.06.2019 11:40, Wemaybewrong
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.)
Answers: 1
Chemistry, 22.06.2019 16:30, jrfranckowiak
At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?
Answers: 1
A science teacher places a sealed microwave bag of popcorn on a balance and measures its mass.
She...
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