Help me please i dont understand

How much heat is needed to change the temperature of 3 grams of gold (c = 0.129 ) from 21°C to 363°C? The answer is expressed to

madam [21]

The correct answer to the question is : B) 132 Joules.

EXPLANATION :

As per the question, the mass of the gold m = 3 gram.

The initial temperature of the gold T = 21 degree celsius.

The final temperature of the gold T' = 363 degree celsius.

Hence, the change in temperature dT = T' - T

= 363 - 21 degree celsius

= 342 degree celsius.

The specific heat of the gold is given as c = $0.129\ J/g^0C$

We are asked to calculate the heat required ( dQ ) to raise the temperature of gold.

The heat required for this is calculated as -

dQ = mcDT

= 3 × 342 × 0.129 J

= 132.354 J

≈ 132 J

Hence, the correct answer is 132 J.

8 0

3 years ago

Read 2 more answers

Calculate the total number of Cl atoms in 150mL of liquid Ccl4 (d=1.589g/mL)

GalinKa [24]

Answer:

The total number of Cl atoms in 150mL of liquid CCl4 is 3.73*10²⁴.

Explanation:

First you must determine the mass of CCL4 present in 150mL of CCl4. Density is a quantity that allows us to measure the amount of mass in a certain volume of a substance, whose expression for its calculation is the quotient between the mass of a body and the volume it occupies:

$density=\frac{mass}{volume}$

In this case, the density value of d = 1.589 g/mL. Then, being the volume equal to 150 mL, the value of the mass can be calculated as:

mass= density*volume

mass=1.589 g/mL * 150 mL

mass= 238.35 g

Now, being the molar mass of CCl4 154 g/mol, the number of moles that 238.35 g represents is calculated as:

$moles=\frac{238.35 g}{154 \frac{g}{mol} }$

moles= 1.55

1 mole of the compound CCl4 contains 4 moles of Cl. Then, using a simple rule of three, it is possible to calculate the number of moles of Cl that 1.55 moles of CCl4 contain:

$moles of Cl=\frac{1.55 moles of CCl_{4} *4 moles of Cl}{1 mole of CCl_{4} }$

moles of Cl= 6.2

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance. In this case it can be applied as follows: if 1 mole of Cl contains 6.023*10²³ atoms, 6.2 moles of Cl how many atoms does it contain?

$atoms of Cl=\frac{6.2 moles*6.023*10^{23} atoms}{1 mole}$

atoms of Cl= 3.73*10²⁴

The total number of Cl atoms in 150mL of liquid CCl4 is 3.73*10²⁴.

8 0

3 years ago

In the diagram, each charge is

Jlenok [28]

Answer:

Quick maths

First you find the fafarick and the lalickc and the caprisum and the joinnt

3 0

3 years ago

A small car has a head-on collision with a large truck. Which of the following statements concerning the magnitude of the averag

andrey2020 [161]

Answer:

The small car and the truck experience the same average force.

Explanation:

Here we need to remember two of Newton's laws.

The second one says that:

F = m*a

force equals mass times acceleration.

And the third one says that;

"If an object A exerts a force on object B, then object B must exert a force of equal magnitude and opposite direction back on object A"

From the third law, if the car experiences a force F due to the impact with the truck, then the truck experiences the same force F due to the impact.

But this seems odd, because we would expect to see the car being more affected by the impact, right?

Well, this is explained by the second law.

Suppose that the mass of the car is m, and the mass of the truck is M.

such that M > m

Then for the small car we have:

F = m*a

And for the truck:

F = M*a'

Because the force is the same for both of them, we can write:

m*a = M*a'

a = (M/m)*a'

because M > m, then M/m > 1.

This means that the acceleration that the car experiences is larger than the acceleration for the truck, and this is why we would see that the car seems more affected by the impact, regardless of the fact that both vehicles experience the same force in the impact.

6 0

2 years ago

What is the cow's average velocity to reach the apples?

docker41 [41]

Answer:1.). -0.65

2.). 0.65

Explanation:

3 0

2 years ago