Answer:
The average atomic weight = 121.7598 amu
Explanation:
The average atomic weight of natural occurring antimony can be calculated as follows :
To calculate the average atomic mass the percentage abundance must be converted to decimal.
121 Sb has a percentage abundance of 57.21%, the decimal format will be
57.21/100 = 0.5721 . The value is the fractional abundance of 121 Sb .
123 Sb has a percentage abundance of 42.79%, the decimal format will be
42.79/100 = 0.4279. The value is the fractional abundance of 123 Sb .
Next step is multiplying the fractional abundance to it masses
121 Sb = 0.5721 × 120.904 = 69.169178400
123 Sb = 0.4279 × 122.904 = 52.590621600
The final step is adding the value to get the average atomic weight.
69.169178400 + 52.590621600 = 121.7598 amu
Answer:
71.372 g or 0.7 moles
Explanation:
We are given;
- Moles of Aluminium is 1.40 mol
- Moles of Oxygen 1.35 mol
We are required to determine the theoretical yield of Aluminium oxide
The equation for the reaction between Aluminium and Oxygen is given by;
4Al(s) + 3O₂(g) → 2Al₂O₃(s)
From the equation 4 moles Al reacts with 3 moles of oxygen to yield 2 moles of Aluminium oxide.
Therefore;
1.4 moles of Al will require 1.05 moles (1.4 × 3/4) of oxygen
1.35 moles of Oxygen will require 1.8 moles (1.35 × 4/3) of Aluminium
Therefore, Aluminium is the rate limiting reagent in the reaction while Oxygen is the excess reactant.
4 moles of aluminium reacts to generate 2 moles aluminium oxide.
Therefore;
Mole ratio Al : Al₂O₃ is 4 : 2
Thus;
Moles of Al₂O₃ = Moles of Al × 0.5
= 1.4 moles × 0.5
= 0.7 moles
But; 1 mole of Al₂O₃ = 101.96 g/mol
Thus;
Theoretical mass of Al₂O₃ = 0.7 moles × 101.96 g/mol
= 71.372 g
Several factors affect the rate of a chemical reaction. From the options given factors that affect the rate are:
temperature and concentration of catalysts.
As the temperature increases, also the rate of the reaction increases.
<span>The concentration of a catalysts helps a reaction to proceed more quickly to equilibrium. </span>
Answer:
Swelling of the red blood cells occurs.
Explanation:
- <u>Distilled water makes the blood hypotonic ,. that is a less concentrated solution, to the body tissues including the red blood cells. </u>
- Therefore the water will enter the red blood cells and may cause them to lyse or swell.
- <em>Additionally , water will enter the tissue spaces and cause sweling. </em>
- But in the case of a hypertonic solution , ( a salt or saline solution ) , <em>This swelling does not happen because the concentration of the saline will be equal or more than the blood. </em>
- Thus the water will flow only from the blood to the solution. <u>This will not cause swelling.</u>
- But too much of salt is also not recommended.
