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3 years ago

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A 40.27 g sample of a substance is initially at 24.8 °c. after absorbing 2099 j of heat, the temperature of the substance is 148

.5 °c. what is the specific heat (c) of the substance?

1 answer:

Darina [25.2K]3 years ago

6 0

Q = mCΔT
Q is heat in joules, m is mass, C is specific heat, and delta T is change in temp

2099 J = (40.27g)(C)(148.5 - 24.8) = .421 J / gram K

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Which of the following statements concerning equilibrium constants is true? The equilibrium constant of the reverse reaction is

Brut [27]

Answer:

When the coefficients in a balanced chemical reaction are multiplied by two, the equilibrium constant is not affected.

Explanation:

The equilibrium constant of a reaction is known to remain steady.

Even if all the coefficients of all the species in the reaction are multiplied by two, the value of the equilibrium constant will reamin the same because the equilibrium position will not change as a result of that.

3 0

3 years ago

Enter your answer in the provided box. From the data below, calculate the total heat (in J) needed to convert 0.304 mol of gaseo

diamong [38]

Answer:

-35,281.5 J

Explanation:

To convert the gaseous ethanol to liquid ethanol, three steps will occur. First, it will lose heat and the temperature will decrease until its boiling point, so from 300.0°C to 78.5°C. Thus, more heat will be lost, but now, with the temperature constant, so the gas will be converted to liquid. And then, the liquid will lose heat to decrease the temperature from 78.5°C to 25.0°C.

The total heat loss is the sum of the heats of each step. Because the heat is being removed from the system, it's negative. The first and last step occurs with a change in temperature, and so the heat is calculated by:

Q = m*c*ΔT

Where m is the mass, c is the specific heat of the gas (first step) or liquid (last step), and ΔT the temperature variation (final - initial). The mass of ethanol is the molar mass 46.07 g/mol multiplied by the number of moles, so:

m = 46.07 * 0.304 = 14.00 g

The second step occurs without a change in temperature, and the heat is then:

Q = -n*ΔH°vap

Where n is the number of moles, ΔH°vap is the heat of vaporization, and the minus signal indicates that the heat is being lost. Then, the heat of each step is:

Q1 = 14.00*1.43*(78.5 - 300,0) = -4434.43 J

Q2 = -0.304*40.5 = -12.312 kJ = -12312 J

Q3 = 14.00*2.45*(25.0 - 78.5) = -1835.05 J

Q = Q1 + Q2 + Q3

Q = -35,281.5 J

5 0

3 years ago

What is the ionic formula of the compound formed by Co3+ and the phosphorus ion? What is the name of the compound formed based o

klasskru [66]

Answer: The ionic formula of compound is $CoP$ and the name is cobalt phosphide.

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Here element Co is having an oxidation state of +3 called as $Co^{3+}$ cation and phosphprous forms $P^{3-}$ anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral $CoP$

The nomenclature of ionic compounds is given by:

1. Positive is written first followed by the oxidation state of metal in roman numerals in square brackets.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

Thus the name of $CoP$ is cobalt phosphide.

4 0

3 years ago

What is the molar solubility of agcl in 0. 30 m nacl at 25°C. ksp for agcl is 1. 77 × 10^-10.

Rzqust [24]

Molar solubility of AgCl will be 0.59 × $10^{-10}$ M.

The amount of a chemical that can dissolve in one liter of a solution before reaching saturation is known as its molar solubility. This implies that the quantity of a substance it can disintegrate in a solution even before the solution becomes saturated with that particular substance is determined by its molar solubility.

A compound's molar solubility would be the measure of how many moles of such a compound must dissolve to produce one liter of saturated solution. The molar solubility unit will be mol L-1.

Calculation of molar solubility:

Given data:

M = 0.30 M

$K_{sp}$ = 1.77 × $10^{-10}$

The reaction can be written as:

AgCl ⇔ $Ag^{+} + Cl^{-}$

s s (s+0.30)

$K_{sp}$ = [ $Ag^{+}$ ]+ [ $Cl^{-}$ ]

1.77 × $10^{-10}$ = s (0.30)

s = 1.77 × $10^{-10}$ / 0.3

s = 0.59 × $10^{-10}$ M

Therefore, molar solubility of AgCl will be 0.59 × $10^{-10}$ M.

To know more about molar solubility

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3 0

1 year ago

What gets reduced in an electrolytic cell made with nickel and copper electrodes?

jekas [21]

Answer:

D. Ni²⁺

Explanation:

We know at once that the answer cannot be A or C, because Ni and Cu are already in their lowest oxidation states.

The correct answer must be either B or D.

An electrolytic cell is the opposite of a galvanic cell. In the former, the reaction proceeds spontaneously. In the latter, you must force the reaction to occur.

One strategy to solve this problem is:

Look up the standard reduction potentials for the half reaction·
Figure out the spontaneous direction.
Write the equation in the reverse direction.

1. Standard reduction potentials

E°/V

Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419

Ni²⁺ + 2e⁻ ⟶ Ni; -0.257

2. Galvanic Cell

We reverse the direction of the more negative half cell and add.

<u>E°/V </u>

Ni ⟶ Ni²⁺ + 2e⁻; 0.257

<u>Cu²⁺ + 2e⁻ ⟶ Cu; </u> 0.3419

Ni + Cu²⁺ ⟶ Cu + Ni²⁺; 0.599

This is the spontaneous direction.

Cu²⁺ is reduced to Cu.

3. Electrochemical cell

<u>E°/V</u>

Ni²⁺ + 2e⁻ ⟶ Ni; -0.257

<u>Cu ⟶ Cu²⁺ + 2e⁻; </u> <u>-0.3419</u>

Cu + Ni²⁺ ⟶ Ni + Cu²⁺; -0.599

This is the non-spontaneous direction.

Ni²⁺ is reduced to Ni in the electrolytic cell.

8 0

3 years ago