Which of the following are mixtures? Salt, air, water salt water

What pressure (in atmospheres) does a gas exert when at 385 mm of Hg?

Westkost [7]

To find out the pressure in atm. You must divide 385 by 760. So pressure in atmospheres equals 385/760.

6 0

3 years ago

What is the molar mas of zinc

Black_prince [1.1K]

The molar mass of Zinc is 65.38 u

Hope this helps :)

3 0

3 years ago

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Imagine you are handed a mineral sample. It breaks with a conchoidal fracture, but displays no cleavage. It does not react with

Shalnov [3]

Answer:

Quartz.

Explanation:

According to the characteristics given in the question the mineral must surely be Quartz.

Quartz does not react with hydrochloric acid.

Its is pink in color and has anon metallic luster. It has a specific gravity of 2.65. Quartz is continuous framework of SiO4 , with each oxygen being shared with two tetrahedra, giving an overall chemical formula of SiO2.

7 0

3 years ago

A 150.0 mL sample of an aqueous solution at 25°C contains 15.2 mg of an unknown nonelectrolyte compound. If the solution has an

inysia [295]

Answer: The molar mass of the unknown compound is 223.2 g/mol

Explanation:

To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

$\pi=iMRT$

where,

$\pi$ = osmotic pressure of the solution = 8.44 torr

i = Van't hoff factor = 1 (for non-electrolytes)

M = molarity of solute = ?

R = Gas constant = $62.3637\text{ L torr }mol^{-1}K^{-1}$

T = temperature of the solution = $25^oC=[273+25]=298K$

Putting values in above equation, we get:

$8.44torr=1\times M\times 62.3637\text{ L. torr }mol^{-1}K^{-1}\times 298K\\\\M=\frac{8.44}{1\times 62.3637\times 298}=4.54\times 10^{-4}M$

To calculate the molecular mass of solute, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

We are given:

Molarity of solution = $4.54\times 10^{-4}M$

Given mass of unknown compound = 15.2 mg = 0.0152 g (Conversion factor: 1 g = 1000 mg)

Volume of solution = 150.0 mL

Putting values in above equation, we get:

$4.54\times 10^{-4}M=\frac{0.0152\times 1000}{\text{Molar mass of unknown compound}\times 150.0}\\\\\text{Molar mass of unknown compound}=\frac{0.0152\times 1000}{150.0\times 4.54\times 10^{-4}}=223.2g/mol$

Hence, the molar mass of the unknown compound is 223.2 g/mol

5 0

3 years ago

C) Define the following terms :- Aufbau Principle

vaieri [72.5K]

Roughly, Aufbau Principle says that in an atom or an ion, electrons enter the shell with low energy first before entering the shell with high energy.

An atom has shells around its nucleus. Electrons enter these shells and orbit around the nucleus of an atom. To say about the properties of these shells, the shell nearest to the nucleus has the lowest energy. The farther the shell from the nucleus, the higher its energy. Aufbau Principle states that electrons enter the closest shell to the nucleus first since it has the lowest energy. When that shell has its maximum number of electrons is can hold, then the next electron will enter the second-closest shell to the nucleus, which has higher energy than the first shell.

3 0

2 years ago