Pure substances found on the periodic table are called what?

Answer:

Melting point of aqueous solution = -10.32 °C

Explanation:

Where,

ΔT_f = Depression in freezing point

k_f = molal depression constant

m = molality

Formula for the calculation of molality is as follows:

density of water = 1 g/mL

density = mass/volume

Therefore,

mass = density × volume

volume = 3 L = 3000 mL

Mass of water = 1 g/mL × 3000 mL

                        = 3000 g

van't Hoff factor (i) for MgCl2 = 3

Substitute the values in the equation (1) to calculate depression in freezing point as follows:

Melting point of aqueous solution = 0 °C - 10.32 °C

                                                          = -10.32 °C

Answer:

The melting point of the solution is - 1.953 °C

Explanation:

In an ideal solution, the freezing point depression is computed as follows:

where:

is the freezing-point depression

is the cryoscopic constant, in this case is equal to 1.86

b is the molality of the solution

i is the van't Hoff factor, number of ion particles per individual molecule of solute, in this case is equal to 3

Molality is defined as follows:

b = moles of solute/kg of solvent

Moles of solute is calculated as follows:

moles of solute = mass of solute/molecular weight of solute

In this case there are 100 g of solute and its molecular weight is 35.5*2 + 24 = 95 g/mole. So, the moles are:

moles of solute = 100 g/(95 g/mol) = 1.05 moles

The mass of solvent is computed as follows:

mass of solvent = density of solvent * Volume of solvent

Replacing with the data of the problem we get:

mass of solvent = 1 kg/L*3 L = 3 kg

Finally, the molality of the solution is:

b = 1.05/3 = 0.35 mol/kg

Then, the freezing-point depression is:

The freezing-point depression is the difference between the melting point of the pure solvent (here water) and the melting point of the solution. We know that the the melting point of water is 0 °C, then:

melting point of water - melting point of the solution = 1.953 °C

melting point of the solution  = 0 °C - 1.953 °C = - 1.953 °C

Answer is (1) - less mass and greater penetrating power.

Alpha particle is a ₂⁴He nucleus while beta particles are electrons. Hence, the mass of alpha particle is greater than the mass of beta particle. But, the penetrating power is higher in beta particle than alpha particle. Alpha particles can be blocked by few papers but beta particles can go through those papers.

Answer: A beta particle has less mass and greater penetrating power.

Explanation:

Penetrating power is the power with which a particle travels or pass through a  substance.

Since, it is known that mass of an alpha particle () is more than the mass of a beta particle (). So, a particle that holds less mass can move easily from one place to another.

Therefore, beta particle can move faster as it has only one electron as compared to 2 protons of an alpha particle. Hence, interaction of beta particles is less with the atoms or materials through which it passes.

Therefore, we can conclude that compared to the mass and the penetrating power of an alpha particle, a beta particle has less mass and greater penetrating power.

Answer:

Type of reactions :

• Decomposition (O is seperated)

Answer;

-The most accurate measurement is made by;

C. Dr. Smith, who measures 13.54 g/mL.

Explanation;

-The absolute density (how much a given volume of the substance weighs) of mercury is 13593 kilograms per cubic meter. It can also be stated as 13.56 g/cm^3. Accuracy measures the nearness of a calculation to the true value.

-In this case; the measurement by Dr. Smith is near the true value 13.56 g/cm^3, as compared to the measurements by other scientists.That is Dr. Chopra, who measures 13.487 g/mL. Dr. Thompson, who measures 13.5 g/mL. and Dr. Tyler, who measures 13.9336 g/mL.