boyles law states that the volumes of a gas will decrease as pressure increases if the temperature remains constant.
charles law states that the volume of a gas will increase as temp increases if the pressure remains constant.
gay-lussacs law states that the pressure increases as temp increases if the volume remains constant.
Answer: 72 grams of 
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number 
of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
According to stoichiometry:
1 mole of 
requires 5 moles of oxygen
0.45 moles of require= 
moles of oxygen
Mass of 
72 grams of are needed to completely burn 19.7 g
Answer:
B) 2Crº + 6e- --> 2Cr3+
Explanation:
The process of oxidation is where electrons are lost. Thus, out of the 2 ions that change charge(Cr and Cu), we must choose the one where the oxidation number increases(which means electrons are lost). Cr goes from an oxidation number of 0 to an oxidation number of 3+, while Cu goes from an oxidation number of 2+ to 0. Thus, we are looking at the half reaction for Cr. Half reactions never have subtracting electrons, so the answer must be B. I am assuming that last plus should be a -->
