All categories

3 years ago

How many moles of atoms are contained in the following 2.25g of k

1 answer:

8 0

Atomic mass (K)= 39.1 amu

therefore:
1 mol (k)---------------------39.1 g
x------------------------------- 2.25 g

x=(1 mol * 2.25 g) / 39.1 g=0.05754....≈0.06 moles

Answer: 0.06 moles.

You might be interested in

How many grams of NH3 are in 45.9

Ostrovityanka [42]

I believe it is 32.3g, I apologize if it is wrong!

7 0

2 years ago

A 59.1 sample of aluminum is put into a calorimeter (see sketch at right) that contains of water. The aluminum sample starts off

Gemiola [76]

Answer:

Specific heat capacity of aluminium is 0,863 J/g°C

Explanation:

Values: 250g of water, aluminum sample starts off at 91.3°C, water starts off at 16.0°C, temperature of the water stops changing it's 19.5°C

In this problem, the heat produced for the aluminium is the same consumed by water. The heat consumed by water is:

Q = C×m×ΔT (1)

Where C is specific heat of water (4,184J/g°C), m is mass of water (250,0g) and ΔT is change in temperature of water (19,5°C-16,0°C = 3,5°C)

Replacing:

Q = 4,184J/g°C×250,0g×3,5°C

Q = 3661 J

Using (1), it is possible to obtain specific heat of aluminium, thus:

Q / (m×ΔT) = C

Where Q is heat (3661J), m is mass (59,1g) and ΔT is change in temperature (91,3°C - 19,5°C( = 71,8°C

Replacing:

3661J / (59,1g×71,8°C) = C

C = 0,863 J/g°C

I hope it helps!

4 0

3 years ago

How many electrons does the isotope oxygen-18 have? 6 8 10 18

Alexxandr [17]

It has 8 electrons I the answer

7 0

3 years ago

Liquid octane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 8.00 g of octane is m

DerKrebs [107]

Answer:

11.3 g of H₂O will be produced.

Explanation:

The combustion is:

2C₈H₁₈ + 25O₂→ 16CO₂ + 18H₂O

First of all, we determine the moles of the reactants in order to find out the limiting reactant.

8 g / 114g/mol = 0.0701 moles of octane

37g / 32 g/mol = 1.15 moles of oxygen

The limiting reagent is the octane. Let's see it by this rule of three:

25 moles of oxygen react to 2 moles of octane so

1.15 moles of oxygen will react to ( 1.15 . 2)/ 25 = 0.092 moles of octane.

We do not have enough octane, we need 0.092 moles and we have 0.0701 moles. Now we work with the stoichiometry of the reaction so we make this rule of three:

2 moles of octane produce 18 moles of water

Then 0.0701 moles of octane may produce (0.0701 . 18)/2= 0.631 moles of water.

We convert the moles to mass → 0.631 mol . 18 g/1mol = 11.3 g of H₂O will be produced.

4 0

2 years ago

B. What do you notice about the number of atoms in one mole?

Doss [256]

Answer:

one mole of atom of any element contains6.022×1033 atoms regardless of the type of elements the mass of one mole of an element depend on what that element is and is equal to atom mass of that element in gram

5 0

3 years ago