What are the elements with atomic numbers from 58 to 71 in the periodic table called?

Identify the number of moles in 369 grams of calcium hydroxide. Use the periodic table and the polyatomic ion resource.

topjm [15]

Answer : The number of moles in 369 grams of calcium hydroxide is, 4.98 moles

Explanation : Given,

Mass of calcium hydroxide = 369 g

Molar mass of calcium hydroxide = 74.093 g/mole

Formula used :

$\text{Moles of calcium hydroxide}=\frac{\text{Mass of calcium hydroxide}}{\text{Molar mass of calcium hydroxide}}$

Now put all the given values in this formula, we get the moles of calcium hydroxide.

$\text{Moles of calcium hydroxide}=\frac{369g}{74.093g/mole}=4.98mole$

Therefore, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles

7 0

4 years ago

Which cause of wildfires is least likely to lead to catastrophic results

sleet_krkn [62]

The third is one: controlled burn

3 0

3 years ago

What are the advantages and disadvantages of fission?

viktelen [127]

Advantages of Nuclear Fission

Nuclear fission provides cheapest energy . Almost 10% of electricity used in the world is obtained from the fission reaction

It offers a low-emission energy solution since there is no carbon dioxide gas emitted during the nuclear fission reaction

A well controlled and maintained nuclear reactor can produce energy for 36 to 40 months so works for .

It is a reliable source of energy as energy is obtained from uranium which is available is plenty.

It provides very concentrations of energy as it can provide large amount of energy from small amount of fuel.

The reaction gives less annual mortality rate of any energy resource with 90 deaths per trillion kilowatt hours

Disadvantages of Nuclear Fission

It is dangerous and also explosive.

It creates harmful and radioactive waste products.

It is not a renewable energy resource like solar and wind energy

It can develop long-term health issues for people exposed to then radioactive waves.

It involves high cost in installation of the reactors.

5 0

3 years ago

15 POINTS PLEASE HELP

Lapatulllka [165]

Answer:

Neutrons = ( Atomic mass – Atomic number ) ( A–Z )

Protons and Electrons are equal to the atomic number

For example Neon,

Mass number (A) = 20

Atomic Number (Z) = 10

Number of Protons = 10

Number of Electrons = 10

Number of Neutrons = ( A–Z ) = 10

Electronic distribution :

K= 2

L= 8

4 0

3 years ago

Which of the following statements explain why the van der Waals equation must be used to describe real gases? X. interactions be

8090 [49]

Answer:

Statements Y and Z.

Explanation:

The Van der Waals equation is the next one:

$nRT = (P + \frac{an^{2}}{V^{2}})(V -nb)$ (1)

The ideal gas law is the following:

$nRT = PV$ (2)

where n: is the moles of the gas, R: is the gas constant, T: is the temperature, P: is the measured pressure, V: is the volume of the container, and a and b: are measured constants for a specific gas.

As we can see from equation (1), the Van der Waals equation introduces two terms that correct the P and the V of the ideal gas equation (2), by the incorporation of the intermolecular interaction between the gases and the gases volume. The term an²/V² corrects the P of the ideal gas equation since the measured pressure is decreased by the attraction forces between the gases. The term nb corrects the V of the ideal gas equation, taking into account the volume occuppied by the gas in the total volume, which implies a reduction of the total space available for the gas molecules.

So, the correct statements are the Y and Z: the non-zero volumes of the gas particles effectively decrease the amount of "empty space" between them and the molecular attractions between gas particles decrease the pressure exerted by the gas.

Have a nice day!

5 0

3 years ago