Answer:
Percentage of oxygen = 30%
Percentage of carbon = 30%
Percentage of hydrogen = 40%
Explanation:
Formula:
Percentage of element = given amount / total amount × 100
Given compound:
C₆H₈O₆
Number of atoms of carbon = 6
Number of atoms of hydrogen = 8
Number of atoms of oxygen = 6
Total number of atoms = 20
Percentage of carbon = 6/20 × 100
Percentage of carbon = 30%
Percentage of Hydrogen = 8/20 × 100
Percentage of Hydrogen = 40%
Percentage of oxygen = 6/20 × 100
Percentage of oxygen = 30%
Atomic mass Ca = 40 a.m.u
1 mole Ca ----------- 40 g
2.5 mols Ca -------- ( mass Ca )
Mass Ca = 2.5 x 40 / 1
Mass Ca = 100 / 1
= 100 g of Ca
hope this helps!
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>
The answer is (4) 4. Germanium is a main group element in group 4A. Therefore, like carbon, it has 4 valence electrons in the ground state.