Answer:
Explanation:
average speed=distance travelled/time taken
distance=speed*time
15*10=150 m
1200 m/min=20 m/s
0.17 minute=10.2 seconds
20*10.2=204 m
2500 cm/s=25 m/s
5000 milliseconds=5 seconds
25*5=125 m
125+150+204=479 m
10.2+5+10=25.2
479/25.2=<u>19.0 </u>
Elements occur naturally in different forms called isotopes. These are the same atoms with the same number of protons but has different number of neutrons. Almost all elements exist in nature as such. The amounts of these isotopes are expressed in terms of percent abundances and since it is in a percentage units, the sum of all the abundances should equate to 100 percent or else the calculation is wrong. This is not true onlt for magnesiun but with all of the elements. The atomic mass of these elements also depends on the percent abundances of the isotopes since it is a weighted average value of the individual masses of the isotopes.
Answer:
Explanation:
It's because of the sun! Bananas are curved so they can retrieve sunlight.
Answer:
0.025 moles of NO₂ will produced
Explanation:
Given data:
Moles of NO₂ formed = ?
Volume of HNO₃ = 25.0 mL
Molarity of HNO₃ = 2 M
Solution:
Chemical equation:
Cu + 4HNO₃ → Cu(NO₃)₂ + 2NO₂ + 2H₂O
Number of moles of HNO₃:
Molarity = number of moles / volume in L
2M = number of moles / 0.025 L
Number of moles = 2 M × 0.025 L
Number of moles = 0.05 mol
Now we will compare the moles of HNO₃ with NO₂ from balance chemical equation.
HNO₃ : NO₂
4 : 2
0.05 : 2/4×0.05 =0.025
0.025 moles of NO₂ will produced.
Answer:
a. Theoretical yield = 8.81 g
b. 77 %
Explanation:
We begin from the reaction:
2Fe (s) + 3Cl₂ (g) → 2FeCl₃ (s)
and the excess is the iron, so the limiting reagent is the chlorine.
We convert mass to moles → 5.78 g / 70.90 g/mol = 0.0815 mol
Ratio is 3:2 so we think this:
From 3 moles of chlorine, I can produce 2 moles of Iron (III) chloride
Then 0.0815 moles would produce (0.0815 . 2) /3 = 0.0543 moles
This is the theoretical yield. We convert the moles to mass:
0.0543 mol . 162.2 g /mol = 8.81 g
If the reaction yields 6.79 g of FeCl₃ and the theoretical yield is 8.81 g ,we can obtain the percent yield: (6.79 / 8.81) . 100 = 77 %
