Answer:
7.82x10^24 molecules of water
Explanation:
H2O=18.015 g/mol Avogadro's #=6.022x10^23 molecules
0.234L x 1000g/1L x 1 mol H2O/18.015 g x 6.022x10^23 = 7.82x10^23 molecules of water
Answer:
3.46x10⁴
Explanation:
Hello,
In this case, we can see that the number 34,560 has five significant figures, it means that if we want to write it with three, we must take the 3, 4 and 5 only. Nevertheless, since the 6 after the five is greater than 5, we can round such five to 6, so we obtain:
346
However, the decimal places cannot get lost, therefore, we move the given thousand to the three, so the number turns out:
3.46x10⁴
Best regards.
If 1000 ml (1 L) of CH₃COOH contain 1.25 mol
let 250 ml of CH₃COOH contain x
⇒ x =
= 0.3125 mol
∴ moles of CH₃COOH in 250ml is 0.3125 mol
Now, Mass = mole × molar mass
= 0.3125 mol × [(12 × 2)+(16 × 2)+(1 × 4)] g/mol
= 18.75 g
∴ Mass of CH₃COOH present in a 250 mL cup of 1.25 mol/L solution of vinegar is <span>18.75 g</span>