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2 years ago

Which statement correctly describes electrochemical cells?

Chemistry

1 answer:

hoa [83]2 years ago

3 0

Answer: C. Electrochemical cells involve oxidation-reduction reactions.

Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.

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If it takes 22974 J to heat 96.5 g of a substance from 13.46°C to 73.86 °C, what is the specific heat of the substance?

yulyashka [42]

The specific heat capacity, C, of the substance is 3.94 $\frac{J}{g-^oC}$ . To raise one gram of a substance by one degree Celsius, a specific amount of heat must be absorbed. This is called the specific heat of the substance. The higher the specific heat of a substance, the more energy is needed to increase its temperature and vice versa.

Further Explanation:

The specific heat capacity, C, of a substance is related to the amount of substance and the temperature change using the following equation

$q \ = \ mC(T_{f}-T_{i})$

where

q = amount of heat absorbed (usually in J)

m = amount of substance (in g)

C = specific heat capacity (in $\frac{J}{g-^oC}$ )

T(f) = final temperature

T(i) = initial temperature.

To answer the problem, we sort the given information:

q = 22974 J (5 significan figures)

m = 96.5 g (3 significant figures)

C = ?

T(f) = 73.86 °C (4 significant figures)

T(i) = 13.46 °C (4 significant figures)

Then, to find C, rearrange the equation:

$C \ = \frac{q}{m(T_{f} \ - \ T_{i})}$

Plug in the values to the equation above to get the value of C.

$C \ = \ \frac{22974 \ J}{96.5 \ g \ (73.86 \ \ -13.46 \°C)} \\C \ = \ \frac{22974 \ J}{96.5 \ g \ (60.4\°C)} \\C \ = \ \frac{22974 \ J}{5828.6 \ g -\°C} \\C \ = \ 3.941598 \ \frac{J}{g -\°C} \\$

Since the least number of significant figures in the given is 3, then the final answer must have 3 significant figures, too. Therefore,

$\boxed {C = 3.94 \ \frac{J}{ g -\°C}}$

Learn More:

1. Learn more about heat capacity brainly.com/question/8828503

2. Learn more about calorimetry brainly.com/question/8168263

3. Learn more about heat of reaction brainly.com/question/10122365

Keywords: heat capacity, specific heat, calorimetry

4 0

2 years ago

How many moles of air must escape from a 10-m  8.0-m  5.0-m room when the temperature is raised from 0c to 20c? assume the p

slega [8]

Data:

p = 1 atm
V = 10 m * 8 m * 5 m = 400 m^3 = 400,000 liter

To = 0 + 273.15K = 273.15K
Tf = 20 + 273.15K = 293.15K

No - Nf =?

2) Formula

pV = NRT => N = pV / (RT)

3) solution

No = pV / (RTo)

Nf = pV / (RTf)

=> No - Nf = [pv / R] [ 1 / To - 1 / Tf ]

=> No - Nf = [1atm*400,000liter / 0.0821 atm*liter/K*mol ] [ 1 / 273.15 - 1 / 293.15]

No - Nf = 1216.9 moles ≈ 1217 moles

Answer: 1217 moles

3 0

2 years ago

How many moles are in 1.2x10^3 grams of ammonia(NH3) ?

miskamm [114]

Answer : The number of moles present in ammonia is, 70.459 moles.

Solution : Given,

Mass of ammonia = $1.2\times 10^3g$

Molar mass of ammonia = 17.031 g/mole

Formula used :

$\text{Moles of }NH_3=\frac{\text{ given mass of }NH_3}{\text{ molar mass of }NH_3}$

$\text{Moles of }NH_3=\frac{1.2\times 10^3g}{17.031g/mole}=70.459moles$

Therefore, the number of moles present in ammonia is, 70.459 moles.

5 0

2 years ago

Read 2 more answers

Convert 6.620 × 102 kg to units of mg.

Neko [114]

Answer:

675,240

Explanation:

3 0

2 years ago

Identify the single displacement reaction. 2H 2 + O 2 ⟶ 2H 2O Al 2S 3 ⟶ 2Al + 3S Cl 2 + 2KBr ⟶ 2KCl + Br 2 C 4H 12 + 7O 2 ⟶ 6H 2

ozzi

Answer: $Cl_2+2KBr\rightarrow 2KCl+Br_2$

Explanation:

A single displacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

$Cl_2+2KBr\rightarrow 2KCl+Br_2$

Synthesis reaction is defined as the reaction where substances combine in their elemental state to form a single compound. $2H_2+O_2\rightarrow 2H_2O$

Decomposition reaction is defined as the reaction where a single substance breaks down into two or more simpler substances.

$Al_2S_3\rightarrow 2Al+3S$

Combustion is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.

$C_4H_{12}+7O_2\rightarrow 6H_2O+4CO_2$

6 0

2 years ago