Answer:
Q1. a) 4Al + 3O₂ ➟ 2Al₂O₃
b) 7.4 moles
c) 11.1 moles
Explanation:
To balance an equation, ensure that the total number of atoms of each element on both sides are equal.
Al + O₂ ➟ Al₂O₃
On the left side of the arrow, you would find the reactants while the product(s) is found on the left hand side.
<u>Reactants</u>
Al atoms: 1
O atoms: 2
<u>Product</u>
Al atoms: 2
O atoms: 3
After balancing,
4Al + 3O₂ ➟ 2Al₂O₃
We have 4 Al atoms and 6 O atoms on both sides.
b) The balanced equation tells us the mole ratio of Al to Al₂O₃.
Al: Al₂O₃
= 4: 2 (÷2 throughout)
= 2: 1
This means that for every 1 mole of Al₂O₃, 2 moles of Al is needed.
Since we need 3.7 moles of Al₂O₃,
number of moles of Al needed
= 2×3.7
= 7.4
c) 4Al + 3O₂ ➟ 2Al₂O₃
For every 4 moles of Al, 3 moles of O are needed.
For each mole of Al,
number of moles of O needed
= 3÷4
= 0.75
For 14.8 moles of Al,
number of moles of O required
= 0.75 ×14.8
= 11.1
Answer:
4.81×10¹⁰ atoms.
Explanation:
We'll begin by converting 3.2 pg to Ca to grams (g). This can be obtained as follow:
1 pg = 1×10¯¹² g
Therefore,
3.2 pg = 3.2 pg × 1×10¯¹² g / 1 pg
3.2 pg = 3.2×10¯¹² g
Therefore, 3.2 pg is equivalent to 3.2×10¯¹² g
Next, we shall determine the number of mole in 3.2×10¯¹² g of Ca. This can be obtained as follow:
Mass of Ca = 3.2×10¯¹² g
Molar mass of Ca = 40.08 g/mol
Mole of ca=.?
Mole = mass /molar mass
Mole of Ca = 3.2×10¯¹² / 40.08
Mole of Ca = 7.98×10¯¹⁴ mole.
Finally, we shall determine the number of atoms present in 7.98×10¯¹⁴ mole of Ca. This can be obtained as illustrated below:
From Avogadro's hypothesis,
1 mole of Ca contains 6.02×10²³ atoms.
Therefore, 7.98×10¯¹⁴ mole of Ca will contain = 7.98×10¯¹⁴ × 6.02×10²³ = 4.81×10¹⁰ atoms.
Therefore, 3.2 pg of Ca contains 4.81×10¹⁰ atoms.
Explanation:
-plants that can absorb copper ions are grown on soil with low grade copper ores.
-the plants are burned and the copper compounds are within the Ash.
-copper ions can be leached from the Ash by adding sulphuric acid, this makes a solution of copper sulphate
-the displacement of scrap iron makes pure copper metals.
Answer:
this is false took the test
Explanation:
Answer:
Concentration of the first solution: approximately 0.200 mol/L.
Concentration of the diluted solution: approximately 0.0250 mol/L.
Explanation:
Refer to a modern periodic table for relative atomic mass data:
- H: 1.008;
- S: 32.06;
- O: 15.999.
Formula mass of sulfuric acid :
.
Number of moles of in of this substance:
.
Convert cubic centimeters to liters:
.
.
.
Concentration of this solution:
.
While both the volume and the concentration of the solution changes when it is diluted, the number of moles of in this solution will stay the same. Number of moles of in this of concentrated solution:
.
That will be the same as the number of moles of in the diluted solution.
Concentration of this solution after it is diluted to :
.