What is 10x20=???????????? I NEEED HELP

What is the pH of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 M? Show your calculation.

Nastasia [14]

Answer:

9.00

Explanation:

Data:

[H⁺] = 1.0 × 10⁻⁹ mol·L⁻¹

Calculation:

pH = -log[H⁺] = -log(1.0 × 10⁻⁹) = -log(1.0) - log(10⁻⁹) = -0.00 - (-9) = -0.00 + 9 = 9.00

7 0

3 years ago

What is the predicted change in the boiling point of water when 1.50 g of

dezoksy [38]

Answer:

0.00735°C

Explanation:

By seeing the question, we can see the elevation in boiling point with addition of BaCl₂ in water

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$\textsf {While} \: \sf {\Delta T_b} \: \textsf{expression is used} \\ \textsf {for elevation of boiling point}$

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The elevation in boiling point is a phenomenon in which there is increase in boiling point in solution, when the particular type of solute is added to pure solvent.

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$\sf \large \underline{The \: formula \: to \: be \: used \: in \: this \: question \: is} \\ \boxed{T_b = i \times K_b \times m}$

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Where 'i' is van't hoff factor which represents the ratio of observed osmotic pressure and the value to be expected.

and 'i' is 3 (as given in the question)

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'Kb' is molal boiling point constant. And it's value is 0.51°C/mol(given in question)

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'm' represent the molality of solution. Molatity is no. of moles of solution present in 1kg of solution.

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To find molality, we have to divide no. of moles of solute by weight of solution

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While first we need to no. of moles

$\sf \implies no. \: of \: moles = \frac{weight \: of \: solute}{molar \: mass \: of \: solute} \\ \\ \implies \sf no. \: of \: moles = \frac{1.5}{208.23} \\ \\ \sf \implies no. \: of \: moles = 0.0072$

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Now, we will find molality

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$\sf \hookrightarrow molality = \frac{no.\: of \: moles}{weight \: of \: solution} \\ \\ \sf \hookrightarrow molality = \frac{0.072}{1.5} \\ \\ \sf \hookrightarrow molality = 0.048 \: mol {kg}^{ - 1}$

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$\textsf{ \large{ \underline{Now substituting the required values}}}$

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$\sf \longmapsto \Delta T_b = 3 \times 0.51 \times 0.0048 \\ \\ \\ \boxed{ \tt{ \longmapsto \Delta T_b =0.00735{ \degree}C}}$

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Henceforth, the change in boiling point is 0.00735°C.

7 0

2 years ago

40. Write a balanced equation and a net ionic equation for combining AgNO3(aq) and Na2CO3(aq)

ki77a [65]

2AgNO3 (aq) + Na2CO3 (aq) --> Ag2CO3 (s) + 2NaNO3 (aq)

2Ag(+) (aq) + CO3(2-) (aq) --> Ag2CO3 (s)
hope it helps

3 0

4 years ago

Consider this reaction: 2al(s) + 3 cucl2(aq) → 2alcl3(aq) + 3 cu(s) if the concentration of cucl2 drops from 1.000 m to 0.655 m

kirza4 [7]

The average rate of reaction over a given interval can be calculated by taking the difference of concentration on a particular given reactant, and dividing it by the total time. In this case, (1.00 M - 0.655 M)/30 s = 0.0115 M/s, or 0.0115 mol/L-s, and this is the final rate of reaction.

8 0

3 years ago

What is mb for CH3NH2….

drek231 [11]

Answer:

A.) $K_b = \frac{[CH_3NH_3^+][OH^-]}{[CH_3NH_2]}$

Explanation:

The general Kb expression is:

$K_b = \frac{[HA][OH^-]}{[A^-]}$

In this equation

-----> Kb = equilibrium constant

-----> [HA] = acid

-----> [A⁻] = base

Since liquids are not included in equilibrium expressions, H₂O should not be present. The products are in the numerator while the reactant are in the denominator. In this reaction, CH₃NH₂ is acting as a base and CH₃NH₃⁺ is acting as an acid.

As such, the expression is:

$K_b = \frac{[CH_3NH_3^+][OH^-]}{[CH_3NH_2]}$

7 0

2 years ago