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3 years ago

2 questions, please help!!

Chemistry

1 answer:

Amanda [17]3 years ago

7 0

i'd go for universal indicator, bromothymol blue and methyl red

i mean, they have the degrees of acidity (specific color changes)

they have wider ranges of color changes which will lead to the strength of acid

you will know the degree of acidity of the cosmetics

in fact, bromothymol blue is used to detect the slightest level of acid or base in a substance

universal indicator has the pH charts; the range is big so that you can measure the level of acidity effectively

methyl red is sensitive too as the other two mentioned earlier

the other way that's not included in your choices is the pH meter

unlike litmus papers which just have 2 results; either red or blue

phenolphthalein only colorless, pale pink

you won't know the degree of acidity

hope that helps

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How many grams of a 22.9% sugar solution contain 68.5 g of sugar?

777dan777 [17]

The grams of 22.9 % sugar solution that contain 68.5 g of sugar is 299.13 g of solution

calculation

22.9% means that there are 22.9 g of sugar in 100 g of solution.

what about 68.5 g of sugar

- by cross multiplication

=[(68.5 g sugar x 100 g solution) /22.9 g sugar] =299.13 g of solution

Nb; g sugar cancel each other

5 0

3 years ago

Methanol (methyl alcohol, CH₃OH), is a very important industrial chemical. Formerly, methanol was prepared by heating wood to hi

katrin [286]

Answer:

CO(g) + 2H₂(g) → CH₃OH(l)

Explanation:

Carbon monoxide has molecular formula CO, molecular hydrogen has formula H₂, and methanol is CH₃OH.

The reactants are CO and H₂ and the product CH₃OH:

CO(g) + H₂(g) → CH₃OH(l)

To balance the equation, the elements must have the same amount on each side. C and O are balanced, but there is 4H in the product and only 2 in the reactant, so we multiply H₂ for 2:

CO(g) + 2H₂(g) → CH₃OH(l)

And the equation is balanced.

4 0

3 years ago

13,000. cm has how many significant figures?

Svet_ta [14]

Answer:

since there is a decimal point at the end, they are all significant figures so the answer is 5

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4 years ago

Read 2 more answers

A method used by the U.S. Environmental Protection Agency (EPA) for determining the concentration of ozone in air is to pass the

baherus [9]

Answer: 1. $9.08\times 10^{-6}$ moles

2. 90 mg

Explanation:

$O_3(g)+2NaI(aq)+H_2O(l) \rightarrow O_2(g)+I_2(s)+2NaOH(aq)$

According to stoichiometry:

1 mole of ozone is removed by 2 moles of sodium iodide.

Thus $4.54 \times 10^{-6}$ moles of ozone is removed by = $\frac{2}{1}\times 4.54 \times 10^{-6}=9.08\times 10^{-6}$ moles of sodium iodide.

Thus $9.08\times 10^{-6}$ moles of sodium iodide are needed to remove $4.54\times 10^{-6}$ moles of $O_3$

2. $\text{Number of moles of ozone}=\frac{0.01331g}{48g/mol}=0.0003moles$

According to stoichiometry:

1 mole of ozone is removed by 2 moles of sodium iodide.

Thus 0.0003 moles of ozone is removed by = $\frac{2}{1}\times 0.0003=0.0006$ moles of sodium iodide.

Mass of sodium iodide= $moles\times {\text {molar mass}}=0.0006\times 150g/mol=0.09g=90mg$ (1g=1000mg)

Thus 90 mg of sodium iodide are needed to remove 13.31 mg of $O_3$ .

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3 years ago

The Fischer esterification mechanism is examined in this question. The overall reaction is: Benzoic acid, C H 3 O H and H C l re

elena55 [62]

Answer:

See explanation and image attached

Explanation:

Fischer esterification is a type of reaction used to convert carboxylic acids to ester in the presence of excess alcohol and a strong acid which acts as a catalyst. Another final product formed in the reaction is water.

The mechanism for the fischer esterification of Benzoic acid and C H 3 O H in the presence of HCl as the catalyst is shown in the image attached to this answer.

The final products of the reaction are methyl benzoate, water and H^+ as shown in the image attached.

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3 years ago