Answer:
It’s true ( pure).
Explanation:
An element is defined as a pure substance that is not chemically combined with any other elements. An element comprises of mainly the sane type of atoms.
While a compound is a substance that consists of two or more elements which are chemically combined together. This is the main difference between an element and a compound.
The Chemica formula of the product is Na2S which is called sodium sulfide. remember that sodium is a metal and all compounds containing a metal are named with the stock system.
Answer:
0.6258 g
Explanation:
To determine the number grams of aluminum in the above reaction;
- determine the number of moles of HCl
- determine the mole ratio,
- use the mole ratio to calculate the number of moles of aluminum.
- use RFM of Aluminum to determine the grams required.
<u>Moles </u><u>of </u><u>HCl</u>
35 mL of 2.0 M HCl
2 moles of HCl is contained in 1000 mL
x moles of HCl is contained in 35 mL

We have 0.07 moles of HCl.
<u>Mole </u><u>ratio</u>
6HCl(aq) + 2Al(s) --> 2AlCl3(aq) + 3H2(g)
Hence mole ratio = 6 : 2 (HCl : Al
- but moles of HCl is 0.07, therefore the moles of Al;

Therefore we have 0.0233333 moles of aluminum.
<u>Grams of </u><u>Aluminum</u>
We use the formula;

The RFM (Relative formula mass) of aluminum is 26.982g/mol.
Substitute values into the formula;

The number of grams of aluminum required to react with HCl is 0.6258 g.
I think It’s 55 but that’s just me
Answer:
0.846 moles.
Explanation:
- This is a stichiometric problem.
- The balanced equation of complete combustion of butane is:
C₄H₁₀ + 6.5 O₂ → 4 CO₂ + 5 H₂O
- It is clear from the stichiometry of the balanced equation that complete combustion of 1.0 mole of butane needs 6.5 moles of O₂ to produce 4 moles of CO₂ and 5 moles of H₂O.
<u><em>Using cross multiplication:</em></u>
- 1.0 mole of C₄H₁₀ reacts with → 6.5 moles of O₂
- ??? moles of C₄H₁₀ are needed to react with → 5.5 moles of O₂
- The number of moles of C₄H₁₀ that are needed to react with 5.5 moles of O₂ = (1.0 x 5.5 moles of O₂) / (6.5 moles of O₂) = 0.846 moles.