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3 years ago

Please help! (The question is in the picture above)

Chemistry

1 answer:

goldfiish [28.3K]3 years ago

7 0

(i) The pH of HCl is between 0 and 2.
(ii) the presence of Carbon Dioxide turns lime water milky or sees a white precipitate form on the surface of the lime water. Lime water is CaOH and when it reacts with Carbon Dioxide it forms a white solid (precipitate) Calcium Carbonate.
$Ca(OH)_{2} _{(l)} + CO_{2} _{(g)} -----\ \textgreater \ CaCO_{3} _{(s)} + H_{2}O_{(l)}$

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Which traits does the western harvest mouse have that might be adaptive for the environment where it lives?

LuckyWell [14K]

Its tail helps it climb down the tall grasses and lets it swing from the grass like a monkey in a tree

Explanation:

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2 years ago

Which of the following is a synthesis reaction?

nadezda [96]

Synthesis reaction is a reaction where two or more substances combine to form a new compound. <span>It is a reaction which releases energy in the form of heat and light. Therefore, it is an exothermic reaction. </span>From its the definition the correct answer is the third option where carbon dioxide and water combine to form carbonic acid.

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3 years ago

Read 2 more answers

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.

AlekseyPX

Answer:

The pH value of the mixture will be 7.00

Explanation:

Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.

Placing all the given data we obtain,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

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3 years ago

Use the drop-down menus to complete the statements.

Cerrena [4.2K]

What grade is this fora.

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2 years ago

Read 2 more answers

Phenol (C6H5OH) is often used as an antiseptic in mouthwashes and throat lozenges. If a mouthwash has a phenol concentration of

amm1812

Answer:

$M=0.16M$

Explanation:

Hello!

In this case, since the molarity is defined as moles of solute divided by liters of solution, since we have phenol with a molar mass of 94.12 g/mol, we can first compute the moles in 1.5 g of phenol:

$n=1.5g*\frac{1mol}{94.12 g}=0.016mol$

Next, since 1000 mL = 1 L, we notice that the volume of the solution is 0.100 L and therefore, the molarity of such solution turns out:

$M=\frac{n}{V}=\frac{0.016mol}{0.100L}\\\\M=0.16M$

Best regards!

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2 years ago