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3 years ago

In which of the following situations is heat transferred from the source to popcorn kernels by the method of conduction?

Chemistry

1 answer:

faltersainse [42]3 years ago

5 0

Answer:

Kernels are placed in a pan on a stove

Explanation:

Heat transfer by conduction involves the actual movement between particles of the medium. For conduction to occur, the particles must be in contact with the heating medium or the body at a higher temperatures.

For the popcorn kernels to conduct heat using the conduction heat transfer process, the kernels are placed in contact with the heat source using the frying pan. The stove is the heat source.

When put a knife in contact with fire, it is heat transfer by conduction.

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General Chemistry fourth edition by McQuarrie, Rock, and Gallogly. University Science Books presented by Macmillan Learning.

Helen [10]

Answer:

3.07 Cal/g

Explanation:

Step 1: Calculate the heat absorbed by the calorimeter

We will use the following expression.

Q = C × ΔT

where,

Q: heat absorbed

C: heat capacity of the calorimeter (37.60 kJ/K = 37.60 kJ/°C)

ΔT: temperature change (2.29 °C)

Q = 37.60 kJ/°C × 2.29 °C = 86.1 kJ

According to the law of conservation of energy, the heat released by the candy has the same magnitude as the heat absorbed by the calorimeter.

Step 2: Convert 86.1 kJ to Cal

We will use the conversion factor 1 Cal = 4.186 kJ.

86.1 kJ × 1 Cal/4.186 kJ = 20.6 Cal

Step 3: Calculate the number of Cal per gram of candy

20.6 Cal/6.70 g = 3.07 Cal/g

3 0

3 years ago

HELP!!!!!!!!!! PLEASE!!! HELP!!

enyata [817]

Answer:

Ooh sweetie goodluck

Explanation:

May the gods ever be in your favor.

8 0

3 years ago

What is the percent by mass of carbon in acetone, c 3 h 6 o?

Tatiana [17]

In the problem, we are tasked to solved for the amount of carbon (C) in the acetone having a molecular formula of C 3 H 6 O. We need to find first the molecular weight if Carbon (C), Hydrogen (H), Oxygen (O).

Molecular Weight:
C=12 g/mol
H=1 g/mol
O=16 g/mol

To calculate for the percent by mass of acetone, we assume 1 mol of acetone.
%C= $( \frac{3(12 g/mol)}{3(12 g/mol)+6(1 g/mol)+16 g/mol} ) x 100%$
%C=62.07%
Therefore, the percent by mass of carbon in acetone is 62.07%

5 0

3 years ago

Read 2 more answers

A student is asked to standardize a solution of barium hydroxide. He weighs out 0.978 g potassium hydrogen phthalate (KHC8H4O4,

Sav [38]

Answer:

(A) 0.129 M

(B) 0.237 M

Explanation:

(A) The reaction between potassium hydrogen phthalate and barium hydroxide is:

2HA + Ba(OH)₂ → BaA₂ + 2H₂O

Where A⁻ is the respective anion of the monoprotic acid (KC₈H₄O₄⁻).

We convert mass of phthalate to moles, using its molar mass:

0.978 g ÷ 156 g/mol = 9.27x10⁻³ mol = 9.27 mmol

Now we convert mmol of HA to mmol of Ba(OH)₂:

9.27 mmol HA * $\frac{1mmolBa(OH)_{2}}{2mmolHA}$ = 6.64 mmol Ba(OH)₂

Finally we calculate the molarity of the Ba(OH)₂ solution:

6.64 mmol / 35.8 mL = 0.129 M

(B) The reaction between Ba(OH)₂ and HCl is:

2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

So the moles of HCl that reacted are:

17.1 mL * 0.129 M * $\frac{2mmolHCl}{1mmolBa(OH)_2}$ = 4.41 mmol HCl

And the molarity of the HCl solution is:

4.41 mmol / 18.6 mL = 0.237 M

3 0

3 years ago

For the chemical reaction

polet [3.4K]

Answer:

806.3g

Explanation:

Given parameters:

Number of moles of silver nitrate = 4.85mol

Unknown:

Mass of silver chromate = ?

Solution:

2AgNO₃ + Na₂CrO₄ → Ag₂CrO₄ + 2NaNO₃

To solve this problem, we work from the known to the unknown;

The known specie here is AgNO₃ ;

From the balanced chemical equation;

2 moles of AgNO₃ will produce 1 mole of Ag₂CrO₄

4.85 moles of AgNO₃ will produce $\frac{4.85}{2}$ = 2.43moles of Ag₂CrO₄

Mass of silver chromate produced;

mass = number of moles x molar mass

Molar mass of Ag₂CrO₄

Atomic mass of Ag = 107.9g/mol

Cr = 52g/mol

O = 16g/mol

Input the parameters and solve;

Molar mass = 2(107.9) + 52 + 4(16) = 331.8g/mol

So,

Mass of Ag₂CrO₄ = 2.43 x 331.8 = 806.3g

8 0

3 years ago