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3 years ago

What evidence is there that marker ink is a mixture

1 answer:

5 0

Ink can be separated into black and other color pigments. This can be done on filter paper by dotting the marker just above the edge and adding ethyl alcohol, which drags the pigments separately across the paper.

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What energy is based on height?

raketka [301]

Answer:

Potential Energy

Explanation:

Potential energy is also called gravitational potential energy and it is based on the height of an object.

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3 years ago

How to find change in enthalpy

arlik [135]

∆H = m x s x ∆T, where m is the mass of the reactants, s is the specific heat of the product, and ∆T is the change in temperature from the reaction.

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3 years ago

Which sequence shows the different types of electromagnetic waves arranged in an increasing order of their frequency?

Elanso [62]

The answer is A)radio waves, micro waves, visible light, x-rays

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3 years ago

What is kinetic energy?

Natali5045456 [20]

Answer:

<h3>D energy of motion</h3>

Explanation:

Kinetic energy is the energy present in mass in motion

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4 years ago

How many grams of sodium fluoride should be added to 300. mL of 0.0310 M of hydrofluoric acid to produce a buffer solution with

Kisachek [45]

Answer : The mass of sodium fluoride added should be 0.105 grams.

Explanation : Given,

The dissociation constant for HF = $K_a=6.8\times 10^{-4}$

Concentration of HF (weak acid)= 0.0310 M

First we have to calculate the value of $pK_a$ .

The expression used for the calculation of $pK_a$ is,

$pK_a=-\log (K_a)$

Now put the value of $K_a$ in this expression, we get:

$pK_a=-\log (6.8\times 10^{-4})$

$pK_a=4-\log (6.8)$

$pK_a=3.17$

Now we have to calculate the concentration of NaF.

Using Henderson Hesselbach equation :

$pH=pK_a+\log \frac{[Salt]}{[Acid]}$

$pH=pK_a+\log \frac{[NaF]}{[HF]}$

Now put all the given values in this expression, we get:

$2.60=3.17+\log (\frac{[NaF]}{0.0310})$

$[NaF]=0.00834M$

Now we have to calculate the moles of NaF.

$\text{Moles of NaF}=\text{Concentration of NaF}\times \text{Volume of solution}=0.00834M\times 0.300L=0.0025mole$

Now we have to calculate the mass of NaF.

$\text{Mass of }NaF=\text{Moles of }NaF\times \text{Molar mass of }NaF=0.0025mole\times 42g/mole=0.105g$

Therefore, the mass of sodium fluoride added should be 0.105 grams.

4 0

3 years ago