Answer:
During ice ages, the most characteristic change to the planet has been the formation and spread large ice sheets and glaciers across much the Northern Hemisphere.
Answer:
67.1%
Explanation:
Based on the chemical equation, if we determine the moles of sodium carbonate, we can find the moles of NaHCO₃ that reacted and its mass, thus:
<em>Moles Na₂CO₃ - 105.99g/mol-:</em>
6.35g * (1mol / 105.99g) = 0.0599 moles of Na₂CO₃ are produced.
As 1 mole of sodium carbonate is produced when 2 moles of NaHCO₃ reacted, moles of NaHCO₃ that reacted are:
0.0599 moles of Na₂CO₃ * (2 moles NaHCO₃ / 1 mole Na₂CO₃) = 0.1198 moles of NaHCO₃
And the mass of NaHCO₃ in the sample (Molar mass: 84g/mol):
0.1198 moles of NaHCO₃ * (84g / mol) = 10.06g of NaHCO₃ were in the original sample.
And percent of NaHCO₃ in the sample is:
10.06g NaHCO₃ / 15g Sample * 100 =
<h3>67.1%</h3>
Answer:
Molarity = 0.7 M
Explanation:
Given data:
Volume of KCl = 20 mL ( 0.02 L)
Molarity = 3.5 M
Final volume = 100 mL (0.1 L)
Molarity in 100 mL = ?
Solution:
Molarity = number of moles of solute / volume in litter.
First of all we will determine the number of moles of KCl available.
Number of moles = molarity × volume in litter
Number of moles = 3.5 M × 0.02 L
Number of moles = 0.07 mol
Molarity in 100 mL.
Molarity = number of moles / volume in litter
Molarity = 0.07 mol /0.1 L
Molarity = 0.7 M
