Hello!
To find the mass of helium, we need to multiply the total moles by the mass of helium. We are given 2.714 moles of helium, and the mass of helium is about 4.00 grams. Now, we multiply the two values together to get the grams.
2.714 moles x 4.00 grams = 10.856 grams
According to the number of significant figures, 2.714 moles of helium has a mass of 10.9 grams (exact value: 10.856 grams).
Answer:
The pH value of the mixture will be 7.00
Explanation:
Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,
![pH=pK_{a} + log(\frac{[Base]}{[Acid]})](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%20%2B%20log%28%5Cfrac%7B%5BBase%5D%7D%7B%5BAcid%5D%7D%29)
According to the given conditions, the equation will become as follow
![pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%20%2B%20log%28%5Cfrac%7B%5BNa_%7B2%7DHPO_%7B4%7D%20%5D%7D%7B%5BNaH_%7B2%7DPO_%7B4%7D%5D%7D%29)
The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.
Placing all the given data we obtain,


Answer:
all objects will remain at rest, or will continue to move at a constant speed in the same velocity unless acted upon by an unbalanced force. This property is called interia
Explanation:
4V is the necessary voltage to power the electrolysis of molten sodium chloride.
To create sodium metal and chlorine gas, molten (liquid) sodium chloride can be electrolyzed. A Down's cell is the name of the electrolytic cell utilised in the procedure. The liquid sodium ions in a Down's cell are converted to liquid sodium metal at the cathode. Liquid chlorine ions are oxidised to chlorine gas at the anode. Below is an illustration of the reactions and cell potentials:
oxidation:
→
+
E°= -1.36V
reduction:
→
E°= -2.71V
overall :
→
E°
= -4.07V
For this electrolysis to take place, the battery needs to supply more than 4 volts. The only means to obtain pure sodium metal is by this reaction, which also serves as a significant source of chlorine gas generation. Swimming pools and other surfaces are frequently cleaned and disinfected with chlorine gas.
Learn more about sodium chloride here;
brainly.com/question/9811771
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