Note that it says oxygen "gas"
So you need the atomic mass of oxygen gas
Look at your periodic table, you'll see 15.9994 under oxygen
Oxygen gas has a formula of O2 therefore,
(15.9994) times 2= Oxygen gas atomic mass=31.9988
Mol= Mass/Atomic Mass
=62.3 g/ 31.9988 g/mol = 1.95 mol
now look at the ratio of C2H6 and O2, notice there is an invisible number beside each of them, at that "invisible number" is =1
1 C2H6 + 1 O2 -> products
this means that for 1 mol of C2H6, 1 mol of O2 has to react with it
Thus as we have 1.95 moles of O2, we need 1.95 moles of C2H6
According to Arrhenius theory of acid and base, Acids are those substances which when dissolved in water produces protons, while, Bases are those substances which when dissolved in water produces Hydroxyl Ions.
Example of Arrhenius Bases:
NaOH ₍s₎ → Na⁺ ₍aq₎ + ⁻OH ₍aq₎
LiOH ₍s₎ → Li⁺ ₍aq₎ + ⁻OH ₍aq₎
Result:
The only negative ion produced in water when Arrhenius Base is dissolved is ⁻OH (Hydroxyl Ion).
I believe the correct answer would be that electronegativity generally increases moving from left to right across a period. The periodic table of elements is arranged so that trends of the properties of the elements can be shown. For electronegativity, it decreases from right to left which means for the opposite direction it increases.