Answer : The mass of solute in solution is
.
Solution : Given,
Molarity = 0.730 M
Volume of solution = 1.421 L
Molar mass of sodium carbonate = 105.98 g/mole
Formula used for Molarity :

where,
w = mass of solute
M = Molar mass of solute
V = volume of solution in liter
Sodium carbonate is solute and water is solvent.
Now put the given values in above formula, we get the mass of solute in solution.

By rearranging the terms, we get

Therefore, the mass of solute in solution is
.
To calculate number of moles, all you do is divide the given mass by the molecular molar mass:
<span>i.e. 125g / 18g = 6.94444g </span>
<span>Therefore, your answer is (a) 6.94 g</span>
Complete question is;
A drop of water has a volume of approximately 7 × 10⁻² ml. How many water molecules does it contain? The density of water is 1.0 g/cm³.
This question will require us to first find the number of moles and then use avogadro's number to get the number of water molecules.
<em><u>Number of water molecules = 2.34 × 10²¹ molecules</u></em>
We are given;
Volume of water; V = 7 × 10⁻² ml
Density of water; ρ = 1 g/cm³ = 1 g/ml
Formula for mass is; m = ρV
m = 1 × 7 × 10⁻²
m = 7 × 10⁻² g
from online calculation, molar mass of water = 18.01 g/mol
Number of moles(n) = mass/molar mass
Thus;
n = (7 × 10⁻²)/18.01
n = 3.887 × 10⁻³ mol
from avogadro's number, we know that;
1 mol = 6.022 × 10²³ molecules
Thus,3.887 × 10⁻³ mol will give; 6.022 × 10²³ × 3.887 × 10⁻³ = 2.34 × 10²¹ molecules
Read more at; brainly.in/question/17990661
Answer:
In conclusion, the net ionic equation for the reaction between calcium carbonate and hydrochloric acid is CaCO3 solid plus two H+ aqueous react to form Ca2+ aqueous plus CO2 gas plus H2O liquid.