The very first step would be to formulate a testable hypothesis.
The ideal gas law states: 
If we put in the data.

Hope this helps.
r3t40
Hey there!
There are 6.022 x 10²³ particles in 1 mole.
We have 3.55 moles.
6.022 x 10²³ x 3.55
2.14 x 10²⁴
This is how many particles we have.
NaCl has 2 atoms for every unit.
So we multiply this by 2.
2 x 2.14 x 10²⁴ = 4.28 x 10²⁴
There are 4.28 x 10²⁴ atoms in 3.55 moles of sodium chloride.
Hope this helps!
Answer:
it moves faster when heated
Answer is: <span>the mass of the excess reactant (ethane) leftover is 90.135 grams.
</span>Chemical reaction: 2C₂H₆(g) + 7O₂(g) → 4CO₂(g) + 6H₂O<span>(g).
m(</span>C₂H₆) = 152 g.
n(C₂H₆) = m(C₂H₆) ÷ M(C₂H₆).
n(C₂H₆) = 152 g ÷ 30 g/mol.
n(C₂H₆) = 5.067 mol.
m(O₂) = 231 g.
n(O₂) = 231 g ÷ 32 g/mol.
n(O₂) = 7.218 mol; limiting reactant.
From chemical reaction: n(O₂) : n(C₂H₆) = 7 : 2.
n(C₂H₆) = 2 · 7.218 mol ÷ 7.
n(C₂H₆) = 2.0625mol.
Δn(C₂H₆) = 5.067 mol - 2.0625 mol.
Δn(C₂H₆) = 3.0045 mol.
Δm(C₂H₆) = 3.0045 mol · 30 g/mol = 90.135 g.