Which of the following tools is not used for measurement?

A container has a mixture of NO2 gas and N2O4 gas in equilibrium. The chemical reaction between the two gases is described by th

kondaur [170]

Answer: The most likely partial pressures are 98.7MPa for NO₂ and 101.3MPa for N₂O₄

Explanation: To determine the partial pressures of each gas after the increase of pressure, it can be used the equilibrium constant Kp.

For the reaction 2NO₂ ⇄ N₂O₄, the equilibrium constant is:

Kp = $\frac{P(N_{2}O_{4} )}{P(NO_{2} ^{2}) }$

where:

P(N₂O₄) and P(NO₂) are the partial pressure of each gas.

Calculating constant:

Kp = $\frac{38.8}{61.2^{2} }$

Kp = 0.0104

After the weights, the total pressure increase to 200 MPa. However, at equilibrium, the constant is the same.

P(N₂O₄) + P(NO₂) = 200

P(N₂O₄) = 200 - P(NO₂)

Kp = $\frac{P(N_{2}O_{4} )}{P(NO_{2} ^{2}) }$

0.0104 = $\frac{200 - P(NO_{2}) }{[P(NO_{2} )]^{2}}$

0.0104 $[P(NO_{2} )]^{2}$ + $P(NO_{2} )$ - 200 = 0

Resolving the second degree equation:

$P(NO_{2} )$ = $\frac{-1+\sqrt{9.32} }{0.0208}$

$P(NO_{2} )$ = 98.7

Find partial pressure of N₂O₄:

P(N₂O₄) = 200 - P(NO₂)

P(N₂O₄) = 200 - 98.7

P(N₂O₄) = 101.3

The partial pressures are $P(NO_{2} )$ = 98.7 MPa and P(N₂O₄) = 101.3 MPa

3 0

3 years ago

What are two things with the same volume but different masses?

Sati [7]

Answer:

an ice cube and paper cube with the same dimensions

Explanation:

an example is an ice cube and a cube with the same dimensions made of paper. these have the same volume, but different masses because the particles are packed differently and in different amounts.

7 0

3 years ago

You are instructed to create 900. mL of a 0.29 M phosphate buffer with a pH of 7.8. You have phosphoric acid and the sodium salt

Aleksandr [31]

Answer:

B and C

Explanation:

When we have to do a buffer solution we always have to choose the reaction that has the pKa closer to the desired pH value. When we find the pKa values we will obtain:

$pKa_1=-Log[6.9x10^-^3]=2.16$

$pKa_2=-Log[6.2x10^-^8]=7.20$

$pKa_3=-Log[4.8x10^-^13]=12.31$

The closer value is pKa2 with a value of 7.2. Therefore we have to use the second reaction. In which $H_2PO_4^-^1$ is the acid and $HPO_4^-^2$ is the base. Therefore the answer for the first question is B and the answer for the second question is C.

8 0

2 years ago

Which of the following would likely form a heterogeneous mixture? Sugar and waterSalt and waterSand and waterBaking soda and wat

kati45 [8]

Answer:

Sand and water

Explanation:

6 0

3 years ago

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The functional structure of a protein is its _________________ structure, which is ultimately determined by the ________________

Dmitriy789 [7]

Answer:

A.

Explanation:

The tertiary structure of proteins is related to the interactions between the amino acids of the primary structure. Thus, these interactions give it a specific three-dimensional configuration which is very sensitive to functionality.

For example, allosteric inhibitions are related to this concept. When the inhibitor changes the tertiary structure of the protein it loses all activity and for the catalysis of the reaction.

Thus, the primary structure (which is related to the specific sequence of amino acids) will determine the tertiary structure since the chain folds will be a consequence of intra-amino acid interactions.

8 0

3 years ago

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