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3 years ago

Which explains the basis of the biuret test?

1 answer:

3 0

<span>The correct answer is C) under base conditions, copper ions bind to the amino groups of proteins and change color. This test is a chemical one, which means it's testing the chemical properties of an object, specifically to detect peptide bonds. When these bonds are detected, an ion called copper II will bind (as the answer indicates), and will change the blue color of biuret into a violet color.</span>

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If the volume of a gas is 958 mL at 75.0 C, at what temperature would the volume of the gas decrease to 822 mL

zhenek [66]

75.0 degrees Celsius = 75.0 + 273 = 348 K.

Assuming pressure is held constant,

$\frac{958}{348}=\frac{822}{T_{2}} \\ \\ \frac{348}{958}=\frac{T_{2}}{822} \\ \\ T_{2}=\frac{(822)(348)}{958} \approx 299 \text{ K} \\ \\ T_{2} \approx 299-273=\boxed{26^{\circ} \text{ C}}$

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2 years ago

At 298 K the standard enthalpy of combustion of sucrose is -5645 kJ/mol and the standard reaction Gibbs energy is -5798 kJ/mol.

natka813 [3]

Explanation:

The given data is as follows.

T = 298 K, $\Delta H^{o}$ = -5645 kJ/mol

$\Delta G^{o}$ = -5798 kJ/mol

Relation between $\Delta H$ and $\Delta G$ are as follows.

$\Delta G^{o}$ = $\Delta H^{o} - T \Delta S^{o}$

-5798 kJ/mol = -5645 kJ/mol - $298 \times \Delta S^{o}$

-153 kJ/mol = - $298 \times \Delta S^{o}$

$\Delta S^{o}$ = 0.513 kJ/mol K

Now, temperature is $37^{o}C$ = (37 + 273) K = 310 K

Since, $\Delta G$ = $\Delta H^{o} - T \Delta S^{o}$

= $-5645 kJ/mol - 310 K \times 0.513 kJ/mol K$

= (-5645 kJ/mol - 159.03 kJ/mol)

= -5804.03 kJ/mol

As, change in Gibb's free energy = maximum non-expansion work

$\Delta G = \Delta G_{310 K} - \Delta G_{298 K}$

= -5804.03 kJ/mol - (-5798 kJ/mol)

= -6.03 kJ/mol

Therefore, we can conclude that the additional non-expansion work is -6.03 kJ/mol.

5 0

3 years ago

Which distance units are in order from smallest to largest?

Kobotan [32]

Answer:

Explanation:

8 0

3 years ago

Calculate the density in g/cm3 for the mass of 452.1g and volume of 292cm3

3241004551 [841]

Density=mass/volume
d= 452.1/292
d= 1.55g/cm3

8 0

3 years ago

Select the correct answer.

MatroZZZ [7]

Answer: The center of the Milky Way

Explanation: It's located about two-thirds of the way out from the center of the Milky Way which is about 28,000 light–years away.

7 0

3 years ago