Answer:
A. Students made a measurement error, because ending with more products is impossible.
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction. If there is excess mass in the product, the students have made an error of some kind.
Explanation:
According to https://oureverydaylife.com/lemon-juice-stop-apples-browning-21624.html it days that"
Chemical Reaction
Once added to sliced apples, the ascorbic acid, or vitamin C, in lemon juice creates a barrier between the oxygen and the polyphenol oxidase. Until the lemon juice has evaporated or been completely absorbed, the oxygen reacts with the ascorbic acid, preventing the apple from turning brown".
Hi, the question has some missing part. The complete question should be " If the 
of 
is 3.74 and the pH of an 
solution is 3.89, it means that -
(a) ![[HCHO_{2}]=[NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3D%5BNaCHO_%7B2%7D%5D)
(b) ![[HCHO_{2}]> [NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3E%20%5BNaCHO_%7B2%7D%5D)
(c) ![[HCHO_{2}]< [NaCHO_{2}]](https://tex.z-dn.net/?f=%5BHCHO_%7B2%7D%5D%3C%20%20%5BNaCHO_%7B2%7D%5D)
Which of the options are true?"
Answer: Option (c) is true.
Explanation:
is an weak acid-conjugate base buffer. Hence, in accordance with Henderson-Hasselbalch equation-
![pH=pK_{a}(HCHO_{2})+log(\frac{[CHO_{2}^{-}]}{[HCHO_{2}]})](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28HCHO_%7B2%7D%29%2Blog%28%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D%29)
Here, pH = 3.89, of = 3.74
So, ![3.89=3.74+log(\frac{[CHO_{2}^{-}]}{[HCHO_{2}]})](https://tex.z-dn.net/?f=3.89%3D3.74%2Blog%28%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D%29)
or, ![\frac{[CHO_{2}^{-}]}{[HCHO_{2}]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCHO_%7B2%7D%5E%7B-%7D%5D%7D%7B%5BHCHO_%7B2%7D%5D%7D)
= 1.41 (>1)
So, ![[CHO_{2}^{-}]> [HCHO_{2}]](https://tex.z-dn.net/?f=%5BCHO_%7B2%7D%5E%7B-%7D%5D%3E%20%5BHCHO_%7B2%7D%5D)
or, ![[NaCHO_{2}]> [HCHO_{2}]](https://tex.z-dn.net/?f=%5BNaCHO_%7B2%7D%5D%3E%20%5BHCHO_%7B2%7D%5D)
Hence, option (c) is correct.
Answer:
20 x (6.022 x 10^23) atoms in 20 moles of Calcium.
Explanation:
A mole contains 6.022 x 10^23 atoms, which is also known as Avogadro's number, and this number is same for each element. So, there are 20 x (6.022 x 10^23) atoms in 20 moles of Calcium.
Answer:
Reaction products are shown below
Explanation:
- In cannizaro reaction, benzaldehyde produces benzoic acid and benzyl alcohol through disproportion.
- Here, a hydroxyl group first gives a nucleophilc addition at carbonyl center of benzaldehyde.
- Then a hydride transfer takes place to another molecule of benzaldehyde
- Thus, benzoic acid and benzyl alcohol are produced.
- Full reaction mechanism has been shown below
