Answer:
10
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
Thus, from the formula, more the concentration of the hydrogen ions or more the acidic the solution is, the less is the pH value of the solution.
Thus, solution with pH = 3 will be more acidic than solution with pH =4
Thus, concentration of the [H⁺] when pH =3
3 = - log [H⁺]
[H⁺] = 10⁻³ M
For pH = 4, [H⁺] = 10⁻⁴ M
<u>hence, pH = 3 is 10 times more acidic than pH = 4</u>
C) change to water at the same temperature
Explanation:
Adding 334Joules of heat to one gram of ice at STP will cause ice to change to water at the same temperature.
- The heat of fusion is the amount of energy needed to melt a given mass of a solid
- It is also conversely the amount of energy removed from a substance to freeze it.
- The addition of this energy does not cause a decrease or increase in temperature.
- Only a phase change occurs.
Learn more:
Heat of fusion brainly.com/question/4050938
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When the amount of heat gained = the amount of heat loss
so, M*C*ΔTloses = M*C* ΔT gained
when here the water is gained heat as the Ti = 25°C and Tf= 28°C so it gains more heat.
∴( M * C * ΔT )W = (M*C*ΔT) Al
when Mw is the mass of water = 100 g
and C the specific heat capacity of water = 4.18
and ΔT the change in temperature for water= 28-25 = 3 ° C
and ΔT the change in temperature for Al = 100-28= 72°C
and M Al is the mass of Al block
C is the specific heat capacity of the block = 0.9
so by substitution:
100 g * 4.18*3 = M Al * 0.9*72
∴ the mass of Al block is = 100 g *4.18 / 0.9*72
= 19.35 g
No of moles of naoh = 2.40 ÷ (23+16+1) = 0.06mol
no of moles of na2co3 = 0.06 ÷ 2 = 0.03mol
mass of na2co3 = 0.03 × (23×2+12+16×3) = 0.03 × 106 = 3.18g
