Answer:
172 g Al
Step-by-step explanation:
We know we will need a balanced equation with masses and molar masses, so let’s <em>gather all the information</em> in one place.
M_r: 26.98 101.96
4Al + 3O₂ ⟶ 2Al₂O₃
m/g: 325
(a) Calculate the <em>moles of Al₂O₃
</em>
n = 325 g Al₂O₃ × 1 mol Al₂O₃ /39.10 g Al₂O₃
n = 3.188 mol Al₂O₃
(b) Calculate the <em>moles of Al
</em>
The molar ratio is (4 mol Al/2 mol Al₂O₃)
n = 3.188 mol Al₂O₃ × (4 mol Al/2 mol Al₂O₃)
n = 6.375 mol Al
(c) Calculate the <em>mass of Al</em>
m = 6.375 mol Al × (26.98 g Al/1 mol Al)
m = 172 g Al
Note: The answer can have only <em>three</em> significant figures because that is all you gave for the mass of Al₂O₃.
Answer:
Storage battery oe cell
Explanation:
The storage battery or cell is a device that coverts chemical energy into light energy when required.
During charging of battery, there is some chemical changes in the battery and absorb energy. The absorbed energy is converted into electrical energy when connected to an external load.
Hence, the correct answer is "Storage battery or cell".
No I wouldn’t be the same
Answer: Option (1) is the correct answer.
Explanation:
Compounds are the substances which contain two or more different elements.
Similarly, water is a compound as it is made up when two hydrogen atoms combine with one oxygen atom. Compounds can be broken down with the help of chemical reactions.
Hence, the statement water can be broken down by chemical means explains why water is classified as a compound.
Answer:
The balanced equation for this reaction will be
→ 
We can see that 1 mole of methane requires 4 moles of fluorine but we have 0.41 moles of CH4 and 0.56mole of F2
So using the unitary method we will get that
- 1 mole of CH4 → 4 mole of 4 mole of fluorine
- 0.41 mole of methane → 4*0.41 = 1.64 mole of fluorine for complete reaction
but we have only 0.56 mole of fluorine that means fluorine is the limiting reagent and the product will only be formed by only this amount of fluorine.
- 4 moles of fluorine → 1 mole of CF4
- 0.56 mole →
= 0.14mole of CF4
- 4 moles of fluorine → 4 moles of HF
- 0.56 mole of fluorine → 0.56 mole of HF
now to find the heat released we have the formula as
DELTA H = n * Delta H of product - n *delta H of reactant
where n is the moles of the reactant and product.
note: since no information is given about the enthalpies of the species we leave it on general equation also you need to add the product side enthalpy of the species present and similarly on the product side.
