Answer: The percentages of carbon and hydrogen numerically to four significant figures is
and
respectively.
Explanation:
Molar mass of the compound is the mass of 1 mole of compound which is the sum of masses of each element.
Mass of 1 mole of compound= mass of carbon + mass of hydrogen+ = 5(12) + 12(1)= 72 g.
a) Percentage by mass of carbon =
Percentage by mass of carbon =
b) Percentage by mass of hydrogen =
Percentage by mass of hydrogen =
<span>Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. Atomic size is difficult to measure because it has no definite boundary. The electrons surrounding the nucleus exist in an electron cloud.
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13. Nt
14. St
15. St
16. At
17. Nt
Answer:
Explanation:
mass fraction N₂ : He : CH₄ : C₂H₆ : : 15 : 5 : 60 : 20
mole fraction N₂ : He : CH₄ : C₂H₆ : : 15/28 : 5/4 : 60/16 : 20/30
mole fraction N₂ : He : CH₄ : C₂H₆ : : .5357 : 1.25 : 3.75 : .67
Total mole fractions = .5357 + 1.25 + 3.75 + 0.67 = 6.2057
mole fraction of N₂ = .5357 / 6.2057 = .0877
mole fraction of He = 1.25 / 6.2057 = .20
mole fraction of CH₄ = 3.75 / 6.2057 = .6043
mole fraction of C₂H₆ = .67 / 6.2057 = .108
Partial pressure = total pressure x mole fraction
Partial pressure of N₂ = 1200 kPa x .0877 = 105.24 kPa
Partial pressure of He = 1200 kPa x .20 = 240 kPa
Partial pressure of CH₄ = 1200 kPa x .6043 = 725.16 kPa
Partial pressure of C₂H₆ = 1200 kPa x .108 = 129.6 kPa
Answer:
The correct answer is - 2770000 cm.
Explanation:
1 kilometer = 1000 meter
1 meter = 100 centimeter
1 kilometer = 100*1000 cm
1 km = 100000 cm.
then,
27.7 kilometers = 2.77 × 10^6 centimeters
So, 27.7 kilometers = 27.7 × 100000
= 2.77 × 106 or 2770000 centimeters.