Burning charocal is that physical or chemical

What is the percent composition of N in HNO3 ?

bonufazy [111]

Answer:

22.22%

Explanation:

N/HNO3*100

14/63*100

=22.22%

4 0

2 years ago

A buffer solution contains 0.306 M C6H5NH3Br and 0.418 M C6H5NH2 (aniline). Determine the pH change when 0.124 mol HCl is added

Ulleksa [173]

Answer: The pH change of the buffer is 0.30

Explanation:

To calculate the pH of basic buffer, we use the equation given by Henderson Hasselbalch:

$pOH=pK_b+\log(\frac{[\text{conjugate acid}]}{[\text{base}]})$

$pOH=pK_b+\log(\frac{[C_6H_5NH_3^+]}{[C_6H_5NH_2]})$ .....(1)

We are given:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.306M$

$[C_6H_5NH_2]=0.418M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.306}{0.418})\\\\pOH=8.99$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{initial}=14-8.99=5.01$

To calculate the molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles hydrochloric acid solution = 0.124 mol

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of HCl}=\frac{0.124}{1L}\\\\\text{Molarity of HCl}=0.124M$

The chemical reaction for aniline and HCl follows the equation:

$C_6H_5NH_2+HCl\rightarrow C_6H_5NH_3^++Cl^-$

Initial: 0.418 0.124 0.306

Final: 0.294 - 0.430

Calculating the pOH by using using equation 1:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.430M$

$[C_6H_5NH_2]=0.294M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.430}{0.294})\\\\pOH=9.29$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{final}=14-9.29=4.71$

Calculating the pH change of the solution:

$\Delta pH=pH_{initial}-pH_{final}\\\\\Delta pH=5.01-4.71=0.30$

Hence, the pH change of the buffer is 0.30

8 0

2 years ago

Too much can lead to diabetes and can be stored as fat in the body

ohaa [14]

Answer:B.carbohydrates

Explanation:

7 0

2 years ago

Which of the following water solutions would likely have the highest boiling point?

Vedmedyk [2.9K]

Answer:

1m

Explanation:

4 0

3 years ago

What is the volume of 4.78g of O2 gas at STP?

My name is Ann [436]

Answer:

Explanation:

The trick here is to realize that if you know the volume of a gas at STP, you can use the fact that

1

mole of any ideal gas occupies

22.7 L

under STP conditions to calculate how many moles of gas you have in your sample.

Under STP conditions:

1 mole of an ideal gas = 22.7 L

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

In your case, you know that your sample of gas occupies

2.28 L

under STP conditions, which are currently defined as a pressure of

100 kPa

and a temperature of

0

∘

C

.

This means that your sample will contain

2.28

L

⋅

molar volume of a gas at STP



1 mole gas

22.7

L

=

0.10044 moles gas

Now, the molar mass of the gas is the mass of exactly

1

mole of the gas. In your case, you know that you get

3.78 g

for every

0.10044

moles, which means that you have

1

mole

⋅

3.78 g

0.10044

moles

=

37.6 g

Since this is the mass of

1

mole of gas, you can say that the molar mass of the gas is

molar mass = 37.6 g mol

−

1

−−−−−−−−−−−−−−−−−−−−−−−

8 0

2 years ago

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Burning charocal is that physical or chemical​

Burning charocal is that physical or chemical