Explanation:
ᗯᕼᗩT ᑕOᑎᑕᗴᑭT ᗩᖇᗴ ᑌ TᗩᑭKIᑎᘜ ᗩᗷOᑌT......
These are two questions and two answers.
1) Question: Which of the following pairs of reactants will react together to produce water (H2O) as one of the products?
<span>Fe(OH)₃ and CuO
Cu(OH)₂ and H₂S
MgO and Ca(OH)₂
SO₃ and H₂O
</span>
<span>Answer:
</span>
<span>Cu(OH)₂ and H₂S
</span>
Justification:
1) Fe(OH)₃ and CuO: to form water Cu and Fe should react with each other. Being them two metals, they will not do that. So this reaction is not possible.
2) Cu(OH)₂ and H₂S: Being S a non metal and Cu a metal, they can react to form a the salt CuS, and water, as per this equation:
<span>Cu(OH)₂ + H₂S → CuS + 2H₂O
</span>
<span>
3) MgO and Ca(OH)₂: Being Mg and Ca two metals they will not react with each other, so this reaction is not feasible.
</span>
<span>4) SO₃ and H₂O: this is an acid oxide and water reaction which yields to an acid, as per this equation:
</span>
<span>SO₃ + H₂O → H₂SO₄
</span>
Which is not producing water
<span>2) Question: Based on reactivity, which of the following elements can replace
aluminum (Al) in a compound during a single replacement reaction?
B
Ca
Zn
Fe
</span>
Answer: Ca.
Justification:
Only an element more reactive than Al will replace it <span>in a compound during a single replacement reaction.</span>
You may predict that being Ca an alkalyne earth element it is more reactive than Al and so Ca will replace Al.
Else, you have to search a reactivity table, where you will find this order of reactivity among the metals:
Ca more reactive than Al
Al more reactive than Zn
Zn more reactive than Fe.
<span />
Being B a metalloid, its matallic character is low and it is less reactive than the other metals on the list.
The answer is c my friend
<span />
The answer is: both choices a and b.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, the molar mass of fluorine is 38.00 g/mol.
M(F₂) = 2 · Ar(F) · g/mol.
M(F₂) = 2 · 19.00 · g/mol.
M(F₂) = 38.00 g/mol.
Molar mass M represent the mass of a substance (in this example molecule of florine) divided by the amount of substance.
Ar is the atomic weight of a chemical element (in this example fluorine).
