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3 years ago

How do you test pH levels in bottled water?

1 answer:

8 0

You can use a universal indicator. The color of the universal indicator before contact with other chemicals is green, which is the pH of 7. We know that bottled water is pH 7. So when we put a few drops of universal indicator, the color would be green indicating neutral pH.

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At a given temperature, 300m of carbon dioxide has a mass of 5.94kg. What is the density of carbon dioxide at this temperature

erica [24]

I think the would have to be 0.198kg/g

4 0

3 years ago

For a process Arightwards harpoon over leftwards harpoonB, at 25 °C there is 10% of A at equilibrium while at 75 °C, there is 80

Lostsunrise [7]

This question is describing the following chemical reaction at equilibrium:

$A\rightleftharpoons B$

And provides the relative amounts of both A and B at 25 °C and 75 °C, this means the equilibrium expressions and equilibrium constants can be written as:

$K_1=\frac{90\%}{10\%}=9\\\\K_2=\frac{20\%}{80\%} =0.25$

Thus, by recalling the Van't Hoff's equation, we can write:

$ln(K_2/K_1)=-\frac{\Delta H}{R}(\frac{1}{T_2} -\frac{1}{T_1} )$

Hence, we solve for the enthalpy change as follows:

$\Delta H=\frac{-R*ln(K_2/K_1)}{(\frac{1}{T_2} -\frac{1}{T_1} ) }$

Finally, we plug in the numbers to obtain:

$\Delta H=\frac{-8.314\frac{J}{mol*K} *ln(0.25/9)}{[\frac{1}{(75+273.15)K} -\frac{1}{(25+273.15)K} ] } \\\\\\\Delta H=4,785.1\frac{J}{mol}$

Learn more:

5 0

2 years ago

What would you use to measure the height of a sample?

andrew-mc [135]

Answer:

please clear ur ques with image

it's unable to be understood

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3 0

2 years ago

Which of the following statements best describes an animal impacting the hydrologic cycle?

Katena32 [7]

Answer:

When an animal breathes out, water vapor from inside the animal's lungs is released into the air.

Explanation:

The hydrologic cycle is the cycle of water movement throughout the environment. A is the only only one that "recycles" water;

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2 years ago

Why does the TLC tank need to be covered?

photoshop1234 [79]

Answer:

The reason for covering the container is to make sure that the atmosphere in the beaker is saturated with solvent vapour. Saturating the atmosphere in the beaker with vapour stops the solvent from evaporating as it rises up the paper.

5 0

2 years ago

Read 2 more answers