Steel is an example of a pure substance because it is made up of two different metals melted together. (4 points) True False

1. How many moles are contained in 103.4g of sulfuric acid?

sdas [7]

It is b I hope this helps

6 0

3 years ago

How many neutrons and protons are there in the nuclei of the following atoms. a. Li-7 b. O-16 c. Th-232 d. Pu-239

ANEK [815]

Answer:

a.

P = 3 , N = 4

b.

P = 8 , N = 8

c.

P = 90 , N = 142

d.

P = 94 , N = 145

Explanation:

Mass number = Number of protons + Number of neutrons

Also,

Atomic number = Number of protons

Li - 7

Given, Mass number of Lithium = 7

For lithium, atomic number = 3

So,

Number of protons = 3

Number of neutrons = Mass number - Number of protons = 7 - 3 = 4

O - 16

Given, Mass number of oxygen = 16

For oxygen, atomic number = 8

So,

Number of protons = 8

Number of neutrons = Mass number - Number of protons = 16 - 8 = 8

Th - 232

Given, Mass number of Thorium = 232

For Thorium, atomic number = 90

So,

Number of protons = 90

Number of neutrons = Mass number - Number of protons = 232 - 90 = 142

Pu - 239

Given, Mass number of Plutonium = 239

For Plutonium, atomic number = 94

So,

Number of protons = 94

Number of neutrons = Mass number - Number of protons = 239 - 94 = 145

3 0

3 years ago

What is the potential energy of the reactants from the following energy diagram?

slavikrds [6]

The potential energy of the reactants is 200J.
From the energy diagram, the energy of the product formed is 350J; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

5 0

3 years ago

Read 2 more answers

The equilibrium concentrations of the reactants and products are [ HA ] = 0.260 M [HA]=0.260 M , [ H + ] = 2.00 × 10 − 4 M [H+]=

ValentinkaMS [17]

Answer:

pKa of the acid HA with given equilibrium concentrations is 6.8

Explanation:

The dissolution reaction is:

HA ⇔ H⁺ + A⁻

So at equilibrium, Ka is calculated as below

Ka = [H⁺] x [A⁻] / [HA] = 2.00 x 10⁻⁴ x 2.00 x 10⁻⁴ / 0.260

= 15.38 x 10⁻⁸

Hence, by definition,

pKa = -log(Ka) = - log(15.38 x 10⁻⁸) = 6.813

7 0

3 years ago

Determine the molarity of 56.00 grams of aluminum nitrate in 450 milliliters of solution?

SVETLANKA909090 [29]

Answer:

4.62 M

Explanation:

Molarity = moles/volumes (L), so you need to find the moles and the volumes in liters.

Finding the volume is easy because you just have to convert mL to L, so the volume is 0.45 L

Next, find the moles. You can do this by using the molar mass of aluminum to convert the grams to moles. The molar mass of aluminum is 26.98 g/mol.

56 g * (1 mol/26.98 g) = 2.08 mol

Now, divide the moles (2.08) by the volume (.45 L)

Molarity = 4.62 M

3 0

3 years ago