Find the best answers to your questions at Westonci.ca, where experts and enthusiasts provide accurate, reliable information. Explore thousands of questions and answers from a knowledgeable community of experts on our user-friendly platform. Get quick and reliable solutions to your questions from a community of experienced experts on our platform.
Sagot :
Answer:
Following are the responses to the given choices:
Explanation:
For point a:
Using the acid and base which are strong so,
moles of [tex]H^+[/tex] (from[tex]HNO_3[/tex])
[tex]= 24.9\ mL \times 0.100\ M \\\\= \frac{24.9}{1000\ L} \times 0.100\ M \\\\= 2.49 \times 10^{-3} \ mol[/tex]
moles of [tex]OH^{-}[/tex] (from [tex]KOH[/tex])
[tex]= 25.0\ mL \times 0.100\ M \\\\= \frac{25.0}{1000 \ L} \times 0.100 \ M \\\\\= 2.50 \times 10^{-3}\ mol[/tex]
[tex]1\ mol H^{+} \ neutralizes\ 1\ mol\ of\ OH^{-}[/tex]
So, [tex](2.50 \times 10^{-3} mol - 2.49 \times 10^{-3} mol)[/tex] i.e. [tex]1 \times 10^{-5}[/tex] mol of [tex]OH^-[/tex] in excess in total volume [tex](24.9+25.0) \ mL = 49.9 \ mL[/tex] i.e. concentration of [tex]OH^- = 2 \times 10^{-4}\ M[/tex]
[tex]p[OH^{-}] = -\log [OH^{-}] = -\log [2 \times 10^{-4}\ mol] = 3.70[/tex]
Since, [tex]pH + pOH = 14,[/tex]
so,
[tex]\to pH = 14- pOH = 14- 3.70 = 10.30[/tex]
For point b:
moles of [tex]OH^-[/tex] = from point a [tex]= 2.50 \times 10^{-3} \ mol[/tex]
moles of [tex]H^+[/tex](from[tex]HNO_3[/tex]):
[tex]= 25.1 mL \times 0.100 M\\\\ = \frac{25.1}{1000}\ L \times 0.100 \ M\\\\ = 2.51\times 10^{-3} \ mol[/tex]
1 mol [tex]H^+[/tex] neutralizes 1 mol of [tex]OH^-[/tex]
So, [tex](2.51 \times 10^{-3}\ mol - 2.50 \times 10^{-3}\ mol)[/tex] i.e. [tex]1 \times 10^{-5} \ mol \ of\ H^+[/tex] in excess in the total volume of [tex](25.1+25.0) \ mL = 50.1\ mL[/tex] i.e. concentration of[tex]H^+ = 2 \times 10^{-4}\ M[/tex]
Hence, [tex]pH = -\log [H^+] = -\log[2 \times 10^{-4}] = 3.70[/tex]
Thanks for using our platform. We aim to provide accurate and up-to-date answers to all your queries. Come back soon. Thanks for stopping by. We strive to provide the best answers for all your questions. See you again soon. Get the answers you need at Westonci.ca. Stay informed with our latest expert advice.
