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3 years ago

Which of these statements about enzymes is true?

1 answer:

7 0

Enzymes are organic catalysts
and catalysts generally increase rate of reaction by lowering activation energy
C is the answer

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Compounds are different than elements because compounds are–

Andrei [34K]

Answer: Compound are different than elements because compounds are combinations of 2 or more elements.

6 0

3 years ago

An unknown acid has a hydronium ion concentration of 0.00352. what is its ph

Ilia_Sergeevich [38]

Answer:

2.453.

Explanation:

∵ pH = - log[H₃O⁺]

[H₃O⁺] = 0.00352 M.

∴ pH = - log[H₃O⁺] = - log(0.00352) = 2.453.

7 0

3 years ago

A 3.301 mass % aqueous solution of potassium hydroxide has a density of 1.05 g/mL. Calculate the molality of the solution. Give

8_murik_8 [283]

Answer: The molality of potassium hydroxide solution is 0.608 m

Explanation:

We are given:

3.301 mass % of potassium hydroxide solution.

This means that 3.301 grams of potassium hydroxide is present in 100 grams of solution

Mass of solvent = Mass of solution - Mass of solute (KOH)

Mass of solvent = (100 - 3.301) g = 96.699 g

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

$\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams})}$

Where,

$m_{solute}$ = Given mass of solute (KOH) = 3.301 g

$M_{solute}$ = Molar mass of solute (KOH) = 56.1 g/mol

$W_{solvent}$ = Mass of solvent = 96.699 g

Putting values in above equation, we get:

$\text{Molality of KOH}=\frac{3.301\times 1000}{56.1\times 96.699}\\\\\text{Molality of KOH}=0.608m$

Hence, the molality of potassium hydroxide solution is 0.608 m

4 0

3 years ago

9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine

il63 [147K]

Answer:

See explanation

Explanation:

Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.

In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.

Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.

7 0

2 years ago

How many milliliters of nitrogen, N2, would have to be collected at 99.19 kPa and 28oC to have a sample containing 0.015 moles o

Semmy [17]

Answer:

378mL

Explanation:

The following data were obtained from the question:

Pressure (P) = 99.19 kPa

Temperature (T) = 28°C

Number of mole (n) = 0.015 mole

Volume (V) =...?

Next, we shall convert the pressure and temperature to appropriate units. This is illustrated below:

For Pressure:

101.325 KPa = 1 atm

Therefore, 99.19 kPa = 99.19/101.325 = 0.98 atm

For Temperature:

T(K) = T(°C) + 273

T(°C) = 28°C

T(K) = 28°C + 273 = 301K.

Next we shall determine the volume of N2. The volume of N2 can be obtained by using the ideal gas equation as shown below:

PV = nRT

Pressure (P) = 0.98 atm

Temperature (T) = 301K

Number of mole (n) = 0.015 mole

Gas constant (R) = 0.0821atm.L/Kmol.

Volume (V) =...?

0.98 x V = 0.015 x 0.0821 x 301

Divide both side by 0.98

V = (0.015 x 0.0821 x 301) /0.98

V = 0.378 L

Finally, we shall convert 0.378 L to millilitres (mL). This is illustrated below:

1L = 1000mL

Therefore, 0.378L = 0.378 x 1000 = 378mL

Therefore, the volume of N2 collected is 378mL

4 0

3 years ago