when liquid water changes into solid ice, it increases in mass
<span>Ground water depletion is one of the major problems. The best solution is to conserve water that we are having currently and to recycle those wasted water. water conservation can be done in many ways such as reduce the level of pumping the ground water, avoiding the use of chemicals, use of natural fertilizers, rain water saving, pumping water to the tanks from stored rain water in the ground, way of handling the water consuming jobs.</span>
I think it’s C.1/2 because the child could get five fingers like his mother or six fingers like his dad
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
The chemical formula for quartz is SiO₂. It has a molar mass of 60.08 g/mol. We use this to find the moles of quartz.
Moles of quartz = 1.90 g(1 mol/60.08 g) = 0.03162 moles
From the chemical formula, there are 2 moles of Oxygen per 1 mole of SiO₂.
Moles of oxygen = 0.03162 moles*2 = 0.063249 moles O
We use the Avogadro's number, 6.022×10²³ atoms/mole, to find the number of oxygen atoms.
0.063249 moles O * 6.022×10²³ atoms/mole = <em>3.81×10²² atoms of oxygen</em>
