<span>4 Al + 3 O2 → 2 Al2O3
(10.0 g Al) / (26.98154 g Al/mol) = 0.37062 mol Al
(19.0 g O2) / (31.99886 g O2/mol) = 0.59377 mol O2
0.37062 mole of Al would react completely with 0.37062 x (3/4) = 0.277965 mole of O2, but there is more O2 present than that, so O2 is in excess.
((0.59377 mol O2 initially) - (0.277965 mol O2 reacted)) x (31.99886 g O2/mol) =
10.1 g O2 left over</span><span>
</span>
Answer:
0.92 kg
Explanation:
The volume occupied by the air is:
The moles of air are:
The heat required to heat the air by 10.0 °C (or 10.0 K) is:
Methane's heat of combustion is 55.5 MJ/kg. The mass of methane required to heat the air is:
Answer:
You are not using properly the function exponential in your calculator
Explanation:
When a number is too big or too small we use scientific notation. This is a number between 1 a 10 multiplied by a power of 10.
When you are writing 4.5*10^-9 you are actually writing 0.0000000045 in scientific notation.
When you enter this in the calculator you have to use the function EXP after the first two numbers.
Steps: 1) Enter 4.5
2) Enter EXP
3) Enter minus (-)
4) Enter 9
<span>Answer: B. Ionic solids have higher melting points than molecular solids.
</span>
This is because the rest are false, as solids are able to melt, and do have melting points. Also, not all solids have the same melting points.
The theory assumes that collisions between gas molecules and the walls of a container are perfectly elastic, gas particles do not have any volume, and there are no repulsive or attractive forces between molecules .
