density is the kilogram per cubic metre means mass divided by volume.
mathmatically= density= mass/ volume
rough = m/v
Answer:
i would have to add and divide
Explanation:
adding and dividing will get you the answer
Answer: 1.2044 × 10^24
Explanation:
1 mole of calcium is 40 gram
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 atoms, also 1 mole of calcium is 40gram
So, 1 mole of calcium = 6.02 x 10^23 atoms
Also, 1 mole of calcium is 40gram
40 grams of calcium = 6.02 x 10^23 atoms
80.156 grams of calcium = Z atoms
To get the value of Z, cross multiply:
Z atoms x 40 grams = 6.02 x 10^23 atoms x 80.156 grams
40Z = 482.54 x 10^23
Z = (482.54 x 10^23/40)
Z = 12.06 x 10^23
Put result in standard form
Z = 1.206 x 10^24 atoms
Thus, 1.206 x 10^24 atoms of Ca are present in 80.156 grams of Ca
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
