Explanation:
According to the Henderson-Hasselbalch equation, the relation between pH and 
is as follows.
pH = 
where, pH = 7.4 and = 7.21
As here, we can use the nearest to the desired pH.
So, 7.4 = 7.21 + 
0.19 =
= 1.55
1 mM phosphate buffer means ![[HPO_{4}]](https://tex.z-dn.net/?f=%5BHPO_%7B4%7D%5D)
+ ![[H_{2}PO_{4}]](https://tex.z-dn.net/?f=%5BH_%7B2%7DPO_%7B4%7D%5D)
= 1 mM
Therefore, the two equations will be as follows.
= 1.55 ............. (1)
+ = 1 mM ........... (2)
Now, putting the value of from equation (1) into equation (2) as follows.
1.55![[H_{2}PO_{4}] + [tex][H_{2}PO_{4}]](https://tex.z-dn.net/?f=%5BH_%7B2%7DPO_%7B4%7D%5D%20%2B%20%5Btex%5D%5BH_%7B2%7DPO_%7B4%7D%5D)
= 1 mM
2.55 = 1 mM
= 0.392 mM
Putting the value of in equation (1) we get the following.
0.392 mM + = 1 mM
= (1 - 0.392) mM
= 0.608 mM
Thus, we can conclude that concentration of the acid must be 0.608 mM.
Answer:
449.5 g
Explanation:
Silver sulfate- Ag2SO4
M(Ag)=107 g/mol => M(Ag2)=214 g/mol
M(S)=32 g/mol
M(O)=16 g/mol => M(O4)=64 g/mol
M(Ag2SO4)=310 g/mol
n=1.45 mol
m(Ag2SO4)=M(Ag2SO4)*n=310 g/mol *1.45 mol= 449.5 g
the volume will be 0.84mol of Y
The density of helium is 10 ^-3g.cm^-3
7.93 x 10⁶mi
Explanation:
Significant figures are numbers that shows how accurate and precise scientific measurements are reported.
Here are some rules to identifying them;
- All non-zero digits are significant
- zeros between digits are significant
- leading zero before a decimal are not significant
- trailing zero after a decimal are significant
- trailing zero before a decimal point are significant.
The number 7926381 has 7 significant numbers.
To write in the scientific notation, we simply express as N x 10ᵃ
N is the number of significant number
a is the exponent
N here is 7.93
a here is 6
7.93 x 10⁶mi
learn more:
Significant figures brainly.com/question/2746374
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