The Correct choices are :
- 1. The elements have filled valence levels.
- 2. potassium (K) with a 1+ charge
Answer:
1.09 grams
Explanation:
According to the following chemical equation:
HF + NaNO₃ -> HNO₃ + NaF
1 mol of hydrogen fluoride (HF) produces 1 mol of sodium fluoride (NaF). Thus, we first convert from mol to grams by using the molar mass (MM) of each compound:
MM(HF)= (1 g/mol x 1 H) + (19 g/mol x 1 F) = 20 g/mol HF
1 mol HF x 19.9 g/mol HF = 20 g
MM(NaF) = (23 g/mol x 1 Na) + (19 g/mol x 1 F) = 42 g/mol NaF
1 mol NaF x 42 g/mol NaF = 42 g
Thus, from 20 g of HF are produced 42 g of NaF ⇒ 20 g HF/42 g NaF. We multiply this stoichiometric ratio by the mass of NaF produced to calculate the required mass of HF:
20 g HF/42 g NaF x 2.3 g NaF = 1.09 g HF
Therefore, 1.09 grams of HF are necessary to produce 2.3 g of NaF.
Answer:
12.1; acidic
Explanation:
I'm assuming the hydrogen concentration is H+.
So, first we must find pH.
pH = -log[H+]
I simply just plugged in the concentration.
I get 1.9 as the pH. This means that the substance is very acidic since it has a low pH.
Now to find poH.
poH + pH = 14
I simply plugged in once again!
I get 12.1 as the poH. This also determines that the substance is very acidic since it has a high poH.
To solve this problem we use Boyle's law to correlate the varying volume and pressure at constant temperature. Assuming ideal gas law, we use the equation P1/V1= P2/V2. Substituting, 735 mm Hg/ P2= 63.5 ml/69.2 ml. P2 is equivalent thus to 800.97 mm Hg.
