You can solve this problem through dimensional analysis.
First, find the molar mass of NaHCO3.
Na = 22.99 g
H = 1.008 g
C = 12.01 g
O (3) = 16 (3) g
Now, add them all together, you end with with the molar mass of NaHCO3.
22.99 + 1.008 + 12.01 + 16(3) = 84.008 g NaHCO3. This number means that for every mole of NaHCO3, there is 84.008 g NaHCO3. In simpler terms, 1 mole NaHCO3 = 84.008 g NaHCO3.
After finding the molar mass of sodium bicarbonate, now you can use dimensional analysis to solve for the number of moles present in 200. g of sodium bicarbonate.
Cross out the repeating units which are g NaHCO3, and the remaining unit is mole NaHCO3
200. * 1 = 200
200/ 84.008 = 2.38
Notice how there are only 3 sig figs in the answer. This is because the given problem only gave three sig figs.
Your final answer is 2.38 mol NaHCO3.
The one that is not a compound is Cl
The question is incomplete. Complete question is:
<span>Consider the given acid ionization constants. identify the strongest conjugate base.
</span>HNO2(aq) 4.6×10−4
HCHO2(aq) 1.8×10−4
HClO(aq) 2.9×10−8
HCN(aq) 4.9×10−10
.........................................................................................................................
Correct Answer: option
4: HCN(aq) 4.9×10−10
Reason:
According to Lowry and Bronsted theory of acid and base. Stronger the acid, weaker will be the conjugate base.
In present case, ionization constant is highest of HCN i.e. 4.9×
. This signifies that, it is the strongest acid. Hence, conjugate base associated with this acid (i.e.
) is the weakest.
Hydrogen gas(H2) has a molar mass of 2 g. Molar mass of a substance is defined as the mass of 1 mole of that substance. And by 1 mole it is meant a collection of 6.022*10^23 particles of that substance.
So number of moles of H2 are 0.5 in this case. And thus it means there are (6.022*10^23)*0.5 particles( here they are molecules) in 1g of H2.
