Hello,
I'd like to introduce you to the magnet analogy:
-Opposite sides attract
-Same sides repel
The first part applies to chemistry, so positive hydrogen bonds tend to attract to negative adjacent molecules.
Answer:
Q = -14322.77 J
Explanation:
Given data:
Mass of water = 55.0 g
Initial temperature = 87.3°C
Final temperature = 25.0 °C
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.0 °C - 87.3°C
ΔT = - 62.3 °C
Q = 55.0 g×4.18 J/g.°C × - 62.3 °C
Q = -14322.77 J
The complete question;
Match each type of titration to its pH at the equivalence point.
Weak acid, strong base
Strong acid, strong base
Weak base, strong acid
pH less than 7
pH equal to 7
<span>pH greater than 7
</span>Answer:
weak acid, strong base - pH greater than 7
Strong acid, strong base - pH equal to 7
Weak base, strong acid - pH less than 7
Strong acids dissociate completely to give out H⁺ ions.
Strong bases dissociate completely to give out OH⁻ ions.
When strong acids and strong bases are mixed the dissociated H⁺ and OH⁻ ions react and neutralise each other, making the solution neutral.
Weak acids cannot completely dissociate, only a fraction of H⁺ ions are dissociated. Same applies for weak bases.
When weak acid and strong base is mixed, whilst the strong acid completely dissociates, weak base only partially dissociates. Therefore the amount of H⁺ ions is greater than OH⁻ ions, overall pH is more acidic, hence less than 7.
When strong base and weak acid are mixed, strong base completely dissociates giving OH⁻ ions and weak acid only partially dissociates, therefore amount of OH⁻ ions is greater than H⁺ ions, more basic hence pH is greater than 7.
