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>
1mol=6.022x10^23 atoms
3.75mol= 6.022x3.75x10^23 atoms
=2.2583x10^24 atoms
Average speed is total distance divided by total time.
Total distance is 50 m + 150 m + 300 m = 500 m
Total time is 68 s + 35 s + 22 s = 125 s
Average speed is 500 m / 125 s = 4 m/s
M₁=50 g
m₀=60 g
w=100m₁/m₀
w=100*50/60=83.3%
<span>pm stands for picometer and picometers are units which can be used to measure really tiny distances. One picometer is equal to 10^{-12} meters. We know that one centimeter is equal to 10^{-2} m so there are 10^2 cm per meter.
We can change the distance d = 115 pm to units of centimeters.
d = (115 pm) x (10^{-12}m / pm) x (10^2 cm / m)
d = 115 x 10^{-10} cm = 1.15 x 10^{-8} cm
The distance in centimeters is 1.15 x 10^{-8} cm</span>