I think that the answer is A because if you think about water for an example. When water turns into ice, it's still technically water, just the molecules are frozen. The water is physically changed. It could also see why you think it is B but I don't think so completely. It doesn't really make sense to me. So I'd choose A. It's definitely not C or D.
Your gonna half to space this out in order for me to answer if you don’t mind. I’ll answer in the comments
Answer is: 5,9.
Effusion is leakage of gas
through a small hole. Gases with a lower molecular mass effuse more speedy than gases with a higher molecular mass. R<span>elative rates of effusion is related to the molecular mass.
</span>M(O₂) = 32g/mol.
M(CO₂) = 44g/mol.
t₁ = 5s.
t₂ = ?
t₂/t₁ = √(M(CO₂)/M(O₂)).
t₂ = 1,17·5s = 5,9s.
Answer:
<u>7.44 grams CaCl2 will produce 10.0 grams KCl.</u>
Explanation:
The equation is balanced:
I've repeated it here, with the elements corrected for their initial capital letter.
CaCl2( aq) K2CO3( aq) → 2KCl( aq) CaCO3( aq)
This equation tells us that 1 mole of CaCl2 will produce 2 moles of KCl.
If we want 10.0g of KCl, we need to convert that mass into moles KCl by dividing by the molar mass of KCl, which is 74.55 grams/mole.
(10.0 grams KCl)/(74.55 grams/mole) = 0.1341 moles of KCl.
We know that we'll need half that amount of moles CaCl2, since the balanced equation says we'll get twice the moles KCl for every one mole CaCl2.
So we'll need (0.1341 moles KCl)*(1 mole CaCl2/2moles KCl) = 0.0671 moles CaCl2.
The molar mass of CaCl2 is 110.98 grams/mole.
(0.0671 moles CaCl2)*(110.98 grams/mole) = 7.44 grams CaCl2
<u>7.44 grams CaCl2 will produce 10.0 grams KCl.</u>
