How many grams of iron(III) oxide would be required to make 187 g of iron

a book with a mass of 1 kg is dropped from a height of 3 m. what is the potential energy of the book when it reaches the floor?

mafiozo [28]

Well, first of all, the formula for finding potential energy is;
PE=mgh
Where; m is the mass
g is the gravitational force or acceleration due to gravity
h is the height.
Anyway, according to the question, the mass is 1kg, the acceleration due to gravity has a constant value of 10ms² . And the height is 3m. Now you just have to use all these in the formula. So;
mgh= 1 x 10 x 3. That will be 30. And the unit of potential energy is Joule. So the answer is 30 joules. Hope i helped. Have a nice day.

5 0

3 years ago

22. Which one of the following processes has a negative value for AH°?

ss7ja [257]

Answer:

C

Explanation:

A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.

Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.

A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.

C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.

D requires heat. It is not the answer.

4 0

3 years ago

How many grams of material is lost in the aqueous phase if two extractions are carried out on 100 mL of a 5% (m/v) aqueous solut

san4es73 [151]

Answer:

4.94g of material

Explanation:

Partition coefficient (Kp) of a substance is defined as the ratio between concentration of organic solution and aqueous solution, that is:

Kp = 8 = Concentration in Ethyl acetate / Concentration in water

100mL of a 5% solution contains 5g of material in 100mL of water. Thus:

8 = X / 100mL / (5g-X) / 100mL

Where X is the amount of material in grams that comes to the organic phase.

8 = X / 100mL / (5g-X) / 100mL

8 = 100X / (500-100X)

4000 - 800X = 100X

4000 = 900X

4.44g = X

Thus, in the first extraction you will lost 4.44g of material from the aqueous phase.

And will remain 5g-4.44g = 0.56g.

In the second extraction:

8 = X / 100mL / (0.56g-X) / 100mL

8 = 100X / (56-100X)

448 - 800X = 100X

448 = 900X

0.50g = X

In the second extraction, you will extract 0.50g of material

Thus, after the two extraction you will lost:

4.44g + 0.50g = 4.94g of material

6 0

2 years ago

Which source of energy causes most of the water evaporation on Earth’s surface? wind solar gravity electrical

Papessa [141]

Since the sun is the main source of evaporation on earth's surface, then the answer should be Solar since solar refers to the sun. It's usually not visible though because it mostly occurs over oceans where it is not seen from the shores.

6 0

3 years ago

Read 2 more answers

3.311x divided by 10^25 particles= ? moles

algol13

Answer:

5.5 moles of given substance.

Explanation:

The given problem can be solved by using the Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

Solution:

3.311 ×10²⁵ / 6.022 × 10²³ = moles

5.5 moles of given substance.

5 0

3 years ago