The answer is D they have 4 neutrons
I think it is C because photosynthesis converts solar energy
The mole fraction of HNO3 is 0.225
<u>Explanation:</u>
<u>1.</u>Given data
Density = 1.429 /ml
Mass% = 63.01 g HNO3 / 100g of solution
The mass of 63.01 g is in 100 / 1.142 /ml of solution
Or 63.01 g in 55.7 mL
Molarity = 15.39 moles / L
Mass of water in 100g = 100 - 63.01=36.99 g
So 63.01 grams in 36.99 grams of water
So mass of HNO3 in 1000grams of water = 63.01* x 1000 / 36.99 = 1703
Moles of HNO3 in 1000g = 1703 / 63.01 = 27.03 moles
Molality = 27.03 molal (mole / Kg)
Mole fraction = Mole of HN03 / Moles of water + mole of HNO3
Mole of water = 62/ 18 = 3.44
Moles of HNO3 = 63.01 / 63.01 = 1.000
Mole fraction = 1.000 / 3.44 + 1.000 = 0.225
The mole fraction of HNO3 is 0.225
Answer:
40 g NaOH
Step-by-step explanation:x
To make 500 mL of a 2 mol·L⁻¹ solution, the technician must measure the correct mass of NaOH.
Step 1. Calculate the <em>moles of NaOH
</em>
c = n/V Multiply both sides by V
n = Vc
c = 2 mol·L⁻¹
V =0.5 L
n = 0.5 × 2
n = 1 mol NaOH
Step 2. Calculate the <em>mass of NaOH
</em>
The molar mass of NaOH is 40.00 g/mol.
m = 1 × 40.00/1
m = <em>40 g NaOH
</em>
The technician must measure <em>40 g of NaOH</em>.
