2.2 Acids, Bases & Salts
1. This question has 2 part(s).
1.1. Grapes contain tartaric acid.
Place a tick (✓) in the box with the expected value for the pH of tartaric acid and explain your choice.
pH value | |
1 | |
5 | |
7 | |
9 | |
13 |
Explanation ...................................................
1.2. Tim was asked to carry out an experiment to investigate the effect of food on the pH of saliva.
At the start of the experiment the pH of saliva in Tim’s mouth was 6.9. He ate an apple and the pH of his saliva was measured every 5 minutes for 45 minutes.
The results of the experiment are shown in the table below.
Time (minutes) | 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 |
pH | 6.9 | 5.7 | 5.0 | 4.5 | 4.5 | 5.0 | 5.7 | 6.1 | 6.4 | 6.6 |
i) Five points have already been plotted. Complete the graph.
[3]
ii) Use the graph to give the minimum pH value obtained during the experiment.
[1]
iii) Use the graph to predict when the pH of Tim’s saliva will return to its original value.
[1]
Ai এর মাধ্যমে
১০ লক্ষ+ প্রশ্ন ডাটাবেজ
প্র্যাকটিস এর মাধ্যমে নিজেকে তৈরি করে ফেলো
উত্তর দিবে তোমার বই থেকে ও তোমার মত করে।
সারা দেশের শিক্ষার্থীদের মধ্যে নিজের অবস্থান যাচাই
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