<u>Answer: </u>The amount of heat released is 84 calories.
<u>Explanation:
</u>
The equation used to calculate the amount of heat released or absorbed, we use the equation:
where,
Q = heat gained or released = ? Cal
m = mass of the substance = 10g
c = specific heat of aluminium = 0.21 Cal/g ° C
Putting values in above equation, we get:
Q = -84 Calories
Hence, the amount of heat released is 84 calories.
Answer:
Option B. Both have a pH less than 7, but H3PO4 has a lower pH than HCl
Explanation:
Those are acid, so the pH would be < 7.
H₃PO₄ is a weak acid with 3 dissociations
HCl is a strong acid.
pH depends on [H]⁺
H₃PO₄ → 3H⁺ + PO₄⁻³
HCl → H⁺ + Cl⁻
If both acid, have the same concentration, [H⁺]H₃PO₄ > [H⁺]HCl, that's why the pH from the phosphoric will be lower.
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.
I think it’s B 5.54 x 10^2g
