Answer:
The percent by mass of copper in the mixture was 32%
Explanation:
The ammount of HNO₃ used is:
mol HNO₃ = volume * concentration
mol HNO₃ = 0.015 l * 15.8 mol/l
mol HNO₃ = 0.237 mol
According to the reaction, 4 mol HNO₃ will react with 1 mol Cu and produce 1 mol Cu²⁺. Since we have 0.237 mol HNO₃, the amount of Cu that could react would be (0.237 mol HNO₃ * 1 mol Cu / 4 mol HNO₃) 0.06 mol. This reaction would produce 0.060 mol Cu²⁺, however, only 0.010 mol Cu²⁺ were obtained, indicating that only 0.010 mol Cu were present in the mixture. This means that the acid was in excess, so we can assume that all copper present in the mixture has reacted.
Since 0.010 mol of Cu²⁺ were produced, the amount of Cu was 0.01 mol.
1 mol of Cu has a mass of 63.5 g, then 0.01 mol has a mass of:
0.01 mol Cu * 63.5 g / 1 mol = 0.635 g.
Since this amount was present in 2.00 g mixture, the amount of copper in 100 g of the mixture will be:
100 g(mixture) * 0.635 g Cu / 2 g(mixture) = 32 g
Then, the percent by mass of Cu (which is the mass of Cu in 100 g mixture) is 32%
Scientists observe the world around them, from which to draw questions. Their predictions as to the answer are what we call a “hypothesis”. Thus, a scientist’s job is to answer the very hypotheses that they and their piers come up with.
Answer:
H₂S(aq)+ 2 LiOH(aq) → Li₂S(aq) + 2 H₂O(l)
6 HI(aq) + 2 Al(s) → 2 AlI₃(aq) + 3 H₂(g)
2 H₂SO₄(aq) + TiO₂(s) → Ti(SO₄)₂(aq) + 2 H₂O(l)
H₂CO₃(aq) + 2 LiOH(aq) → Li₂CO₃(aq) + 2 H₂O(l)
Explanation:
H₂S(aq)+ 2 LiOH(aq) → Li₂S(aq) + 2 H₂O(l)
This is a neutralization reaction. The products are salt and water.
6 HI(aq) + 2 Al(s) → 2 AlI₃(aq) + 3 H₂(g)
This is a single displacement reaction.
2 H₂SO₄(aq) + TiO₂(s) → Ti(SO₄)₂(aq) + 2 H₂O(l)
This is a neutralization reaction. The products are salt and water.
H₂CO₃(aq) + 2 LiOH(aq) → Li₂CO₃(aq) + 2 H₂O(l)
This is a neutralization reaction. The products are salt and water.
Answer:
- Failed internal wiring
- reaching a hard to get metal item
- keeping a item on a metal surface
Explanation:
Please give me BRAINLIEST :))
valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
