Chemistry, 08.10.2019 04:00 kmacho9726
The air you breathe is made of 21% oxygen and 78% nitrogen. the oxygen in air is the and the nitrogen is the
Answers: 3
Chemistry, 22.06.2019 11:40
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 18:30
The table lists the lattice energies of some compounds.compoundlattice energy (kj/mol)lif –1,036licl –853naf –923kf –821nacl –786which statement about crystal lattice energy is best supported by the information in the table? the lattice energy increases as cations get smaller, as shown by lif and kf.the lattice energy increases as the cations get larger, as shown by lif and licl.the lattice energy decreases as cations get smaller, as shown by nacl and naf.the lattice energy decreases as the cations get smaller, as shown by naf and kf.
Answers: 3
Chemistry, 22.06.2019 21:00
Which answer tells the reason the earth’s climate is getting warmer? too many animals are becoming extinct. large glaciers are melting in antarctica. the earth is moving closer to the sun. driving cars gives off gases that trap heat in the atmosphere.
Answers: 1
The air you breathe is made of 21% oxygen and 78% nitrogen. the oxygen in air is the and the nitrog...
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