Molarity Calculations

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olga nikolaevna [1]

Answer:

Heat or electricity in the atmasphere

Explanation:

4 0

3 years ago

If you combine 230.0 mL 230.0 mL of water at 25.00 ∘ C 25.00 ∘C and 120.0 mL 120.0 mL of water at 95.00 ∘ C, 95.00 ∘C, what is t

Thepotemich [5.8K]

Answer: The final temperature of the mixture is 49°C

Explanation:

To calculate the mass of water, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

For cold water:

Density of cold water = 1 g/mL

Volume of cold water = 230.0 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{230.0mL}\\\\\text{Mass of water}=(1g/mL\times 230.0mL)=230g$

For hot water:

Density of hot water = 1 g/mL

Volume of hot water = 120.0 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{120.0mL}\\\\\text{Mass of water}=(1g/mL\times 120.0mL)=120g$

When hot water is mixed with cold water, the amount of heat released by hot water will be equal to the amount of heat absorbed by cold water.

$Heat_{\text{absorbed}}=Heat_{\text{released}}$

The equation used to calculate heat released or absorbed follows:

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

$m_1\times c\times (T_{final}-T_1)=-[m_2\times c\times (T_{final}-T_2)]$ ......(1)

where,

q = heat absorbed or released

$m_1$ = mass of hot water = 120 g

$m_2$ = mass of cold water = 230 g

$T_{final}$ = final temperature = ?°C

$T_1$ = initial temperature of hot water = 95°C

$T_2$ = initial temperature of cold water = 25°C

c = specific heat of water = 4.186 J/g°C

Putting values in equation 1, we get:

$120\times 4.186\times (T_{final}-95)=-[230\times 4.186\times (T_{final}-25)]$

$T_{final}=49^oC$

Hence, the final temperature of the mixture is 49°C

4 0

4 years ago

An atom emits of wavelength 1.08 meters. what is the energy change occurring in the Atom due to this emission? (Planck’s constan

butalik [34]

To answer this question, we can use the following equation:

$e=\frac{h*c}{lambda}$

where e is the energy change, h is Planck's constant, c is the speed of light (m/s), and lambda is wavelength in meters. So then we can plug in the information:

$e=\frac{(6.626x10^{-34}J*s)(2.998x10^{8}\frac{m}{s})}{1.08m}$

$e=\frac{1.9865x10^{-25}J}{1.08}$

$e=1.84x10^{-25}J$

So the energy that is omitted by the atom is $1.84x10^{-25}J$ .

5 0

3 years ago

A pure substance which can only be separated into two or more simpler substances using chemical changes is called

rosijanka [135]

Answer: Compound . Chemical reactions can divide elements into simpler substances, but they cannot separate elements into simpler substances. Physical or chemical characteristics of substances can be categorised.

Compounds and elements can be created from pure substances. A chemical reaction is required to break down pure substances (elements and compounds) into their component atoms or elements. This is known as the chemical separation process. Physical separation of pure substances is impossible.

Explanation:

What makes something pure substance?

One element or a small number of related compounds make up pure substances. Mixtures are assemblages of many components. Mixtures of two or more substances (or elements) that cannot be visually distinguished from one another are referred to as homogeneous mixtures.

What sort of compound would that be?

A substance made up of two or more components is called a compound. Table salt, water, and carbon dioxide are a few examples of compounds

To know more about pure substance visit ;

brainly.com/question/24462192

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7 0

1 year ago

Calculate the pH at the equivalence point for the titration of 0.110 M methylamine (CH3NH2) with 0.110 M HCl. The Kb of methylam

nikklg [1K]

The reaction between the reactants would be:

CH₃NH₂ + HCl ↔ CH₃NH₃⁺ + Cl⁻

Let the conjugate acid undergo hydrolysis. Then, apply the ICE approach.

CH₃NH₃⁺ + H₂O → H₃O⁺ + CH₃NH₂
I 0.11 0 0
C -x +x +x
E 0.11 - x x x

Ka = [H₃O⁺][CH₃NH₂]/[CH₃NH₃⁺]

Since the given information is Kb, let's find Ka in terms of Kb.

Ka = Kw/Kb, where Kw = 10⁻¹⁴

So,
Ka = 10⁻¹⁴/5×10⁻⁴ = 2×10⁻¹¹ = [H₃O⁺][CH₃NH₂]/[CH₃NH₃⁺]
2×10⁻¹¹ = [x][x]/[0.11-x]
Solving for x,
x = 1.483×10⁻⁶ = [H₃O⁺]

Since pH = -log[H₃O⁺],
pH = -log(1.483×10⁻⁶)
pH = 5.83

4 0

4 years ago