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gulaghasi [49]
3 years ago
14

You wish to construct a buffer of pH=7.0. Which of the following weak acids (w/ corresponding conjugate base) would you select?

Chemistry
1 answer:
Alex17521 [72]3 years ago
3 0

Answer:

C.) HOCl Ka=3.5x10^-8

Explanation:

In order to a construct a buffer of pH= 7.0 we need to find the pKa values of all the acids given below

we Know that

pKa= -log(Ka)

therefore

A) pKa of  HClO2 = -log(1.2 x 10^-2)

=1.9208

B) similarly PKa of HF= -log(7.2 x 1 0^-4)= 2.7644

C)  pKa of HOCl= -log(3.5 x 1 0^-8)= 7.45

D) pKa of HCN = -log(4 x 1 0^-10)=  9.3979

If we consider the  Henderson- Hasselbalch equation for the calculation of the pH of the buffer solution

The weak acid for making the buffer must have a pKa value near to the desired pH of the weak acid.

So, near to value, pH=7.0. , the only option is HOCl whose pKa value is 7.45.

Hence, HOCl will be chosen for buffer construction.

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The number of moles of hydrogen that are needed to produce .253 moles of water​
Brut [27]

Answer:

454

Explanation:

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8 0
3 years ago
What is the mass of 1.7 × 1023 atoms of zinc
fiasKO [112]

We are given with a compound, Zinc (Zn) having a 1.7 x 10 ^23 atoms. We are tasked to solve for it's corresponding mass in g. We need to find first the molecular weight of Zinc, that is

Zn= 65.38 g/mol

Not that 1 mol=6.022x10^{23} atoms, hence,

1.7 x 10 ^23 atoms x 1 mol/6.022x10^{23} atoms x65.38 g/ 1mol

=18.456 g of Zn

 

Therefore, the mass of Zinc 18.456 g

3 0
3 years ago
How many molecules are in 7.62 L of CH4, at 87.5°C and 722 torr
pickupchik [31]

Answer: There are 1.469 \times 10^{23} molecules present in 7.62 L of CH_4 at 87.5^{o}C and 722 torr.

Explanation:

Given : Volume = 7.62 L

Temperature = 87.5^{o}C = (87.5 + 273) K = 360.5 K

Pressure = 722 torr

1 torr = 0.00131579

Converting torr into atm as follows.

722 torr = 722 torr \times \frac{0.00131579 atm}{1 torr}\\= 0.95 atm

Therefore, using the ideal gas equation the number of moles are calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = number of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

PV = nRT\\0.95 atm \times 7.62 L = n \times 0.0821 L atm/mol K \times 360.5 K\\n = \frac{0.95 atm \times 7.62 L}{0.0821 L atm/mol K \times 360.5 K}\\= \frac{7.239}{29.59705}\\= 0.244 mol

According to the mole concept, 1 mole of every substance contains 6.022 \times 10^{23} atoms. Hence, number of atoms or molecules present in 0.244 mol are calculated as follows.

0.244 mol \times 6.022 \times 10^{23}\\= 1.469 \times 10^{23}

Thus, we can conclude that there are 1.469 \times 10^{23} molecules present in 7.62 L of CH_4 at 87.5^{o}C and 722 torr.

5 0
3 years ago
CO, + H2O –H^2 CO^3 The reaction is which type of chemical reaction?​
gulaghasi [49]

Answer:

Combination reaction or synthesis reaction

Explanation:

Given reaction:

                 CO  +  H₂O  →  H₂CO₃

The type of reaction shown above is a combination or synthesis reaction. A combination reaction is one in which a single product is formed from two or more reactants.

In the given reaction carbon monoxide combines with water to produce hydrogen carbonate.

The formation of compounds from the union of their constituent elements falls into this category of reactions.

4 0
3 years ago
Plz hurry fast I need help !!!
Vikki [24]

Answer:

USE SOCRATIC

Explanation:

5 0
3 years ago
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