<span>The state of the helium in its natural form is gaseous and is a chemical element of colorless aspect and belongs to the group of noble gases. The atomic number of helium is 2. The chemical symbol of helium is He. For the following we focus on those elements and relate it with similar chemical properties. Then we find that; Neon, Hydrogen, Boron and Carbon are related to helium, either by proximity in their atomic number or period or by their group.</span>
Answer:
0.07 g/s.
Explanation:
From the question given above, the following data were obtained:
Mass lost = 9.85 g
Time taken = 2 min 30 s
Mean rate =?
Next, we shall convert 2 min 30 s to seconds (s). This can be obtained as follow:
1 min = 60 s
Thus,
2 min = 2 × 60 = 120 s
Therefore,
2 min 30 s = 120 s + 30 s = 150 s
Finally, we shall determine the mean rate of the reaction. This can be obtained as illustrated below:
Mass lost = 9.85 g
Time taken = 150 s
Mean rate =?
Mean rate = mass lost / time taken
Mean rate = 9.85 / 150
Mean rate = 0.07 g/s
Therefore, the mean rate of the reaction is 0.07 g/s
I know for certain, that chloroplast does not belong on that list, chloroplast only belongs inside of plant cells to produce energy required for the plant. I am not sure about the era or er, but chloroplast does not belong.
Hope this helps, if not, comment below please!
Answer:
The mass percentage of nitrogen in the sample is 1.96%.
Explanation:
21.0 mL of 0.150 M HCl
Moles of hydrogen chloride = n
Volume of hydrogen chloride solution = 21.0 mL = 0.021 L
Molarity of the hydrogen chloride = 0.150 M
According to recation, 1 mole of HCl neutralizes 1 mole ammonia.Then 0.00315 moles of HCl will neutrtalize:
of ammonia
1 mole of ammonia has 1 mole of nitrogen atom . Then 0.00315 moles of ammonia will have = 1 × 0.00315 mol = 0.00135 mol
Mass of 0.00315 moles of nitrogen= 0.00315 mol × 14 g/mol = 0.0441 g
Mass of the sample = 2.25 g
The mass percentage of nitrogen in the sample:
