Physical changes<span> only </span>change<span> the appearance of a substance, not its chemical composition. Chemical </span>changes cause<span> a substance to</span>change<span> into an entirely substance with a new chemical formula. Chemical </span>changes<span> are also known as chemical reactions.</span>
0 because you would be floating at the top within seconds and also have fun with the sudden stop
At prevents the apples from the oxygen <span />
The effect of temperature depends upon the extent of rise in temperature (for solids)
However in general if we increase temperature of a substance there will be increase in kinetic energy of the molecules and generally the volume of substance will increase
However there will be no effect on the mass of the substance due to increase / decrease in temperature
Density = mass / volume
As mass will remain constant and volume will increase with temperature the density of solid will generally decrease (very less though)
Answer:
molar composition of oxygen =0.2 (20%)
molar composition of hydrogen = 0.8 (20%)
Explanation:
Since hydrogen and oxygen react according to
2*H₂+ O₂ → 2*H₂O
according to the ideal gas law:
P₁*V=n₁*R*T (initial state)
P₂*V=n₂*R*T (final state)
dividing both equations
P₁/P₂ = n₁/n₂
then since 2 moles of hydrogen react for every mole of oxygen that reacts, thus oxygen that reacted "no" is
no = (n₁-n₂) 1/(1+2) = n₁ (1-n₂/n₁)/3
then
molar composition of oxygen = xo= no/n₁ = (1-n₂/n₁)/3 = (1-P₂/P₁)/3 = (1-0.4 atm/1 atm )/3 = 0.2 (20%)
then
molar composition of hydrogen = xh= 1- xo = 0.8 (20%)
to verify it , the number of initial moles n₁=remaining hydrogen + hydrogen that reacted + oxygen that reacted
and since 2 moles of hydrogen react for every mole of oxygen that reacts n₁= n₂ + (n₁-n₂) (2/3) + (n₁-n₂) (1/3) = n₂ + (n₁-n₂) = n₁