Does drinking water undergo a separation process called straining?
2 answers:
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Answer:
The significance of "Er" in the diagram is :
B.) Threshold energy for reaction
Explanation:
Threshold energy : It is total amount of energy required by the reactant molecule to reach the transition state .
Activation energy : It is the excess energy absorbed by the molecules to reach the transition state.
<u>Activation Energy = Threshold Energy - Average Kinetic Energy</u>
<u>This means Activation energy decreases on increasing kinetic energy</u>
On increasing Temperature average kinetic energy of the molecule increases which reduces the activation energy and the reaction occur faster in that case.
Catalyst also reduces the Activation energy.
<u>Er = Threshshold energy for reaction at 30 degree</u>
<u>Ea = Activation Energy</u>
<u>The given figure shows that the threshold energy decreases on increasing the temperature</u>
<u>Only the molecule having energy greater than Er can react to form product</u>
Answer:
Check the explanation
Explanation:
Answer – Given, acid and there are three Ka values
The transformation of is the second dissociation, so we need to use the Ka2 = 6.2x10-8 in the Henderson-Hasselbalch equation.
Mass of KH2PO4 = 22.0 g , mass of Na2HPO4 = 32.0 g , volume = 1.00 L
First we need to calculate moles of each
Moles of KH2PO4 = 22.0 g / 136.08 g.mol-1
= 0.162 moles
Moles of Na2HPO4 = 32.0 g /141.96 g.mol-1
= 0.225 moles
[H2PO4-] = 0.162 moles / 1.00 L = 0.162 M
[HPO42-] = 0.225 moles / 1.00 L = 0.225 M
Now we need to calculate the pKa2
pKa2 = -log Ka
= -log 6.2x10-8
= 7.21
We know Henderson-Hasselbalch equation
pH = pKa + log [conjugate base] / [acid]
pH = 7.21 + log 0.225 / 0.162
= 7.35
The pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L is 7.35