Coefficient -<br> 2) V205<br> Subscript for V<br> Subscript for 0 -<br> HELPPP

A chemist weighed out 70.8 g of magnesium. Calculate the number of moles of magnesium she weighed out. Round your answer to sign

solniwko [45]

Answer:

2.91 grams of Magnesium

Explanation:

I put a picture . I used the molar mass of magnesium which can be calculated from the periodic table or simply google it. :) I hope it helps - Enrique

8 0

3 years ago

Read 2 more answers

For the equilibrium

Mamont248 [21]

Answer:

Equilibrium concentrations of the gases are

$H_2S=0.596M$

$H_2=0.004 M$

$S_2=0.002 M$

Explanation:

We are given that for the equilibrium

$2H_2S\rightleftharpoons 2H_2(g)+S_2(g)$

$k_c=9.0\times 10^{-8}$

Temperature, $T=700^{\circ}C$

Initial concentration of

$H_2S=0.30M$

$H_2=0.30 M$

$S_2=0.150 M$

We have to find the equilibrium concentration of gases.

After certain time

2x number of moles of reactant reduced and form product

Concentration of

$H_2S=0.30+2x$

$H_2=0.30-2x$

$S_2=0.150-x$

At equilibrium

Equilibrium constant

$K_c=\frac{product}{Reactant}=\frac{[H_2]^2[S_2]}{[H_2S]^2}$

Substitute the values

$9\times 10^{-8}=\frac{(0.30-2x)^2(0.150-x)}{(0.30+2x)^2}$

By solving we get

$x\approx 0.148$

Now, equilibrium concentration of gases

$H_2S=0.30+2(0.148)=0.596M$

$H_2=0.30-2(0.148)=0.004 M$

$S_2=0.150-0.148=0.002 M$

3 0

3 years ago

the law of conversation of (mass/energy) states that the total mass before a chemical reaction is the same as the totally mass a

Nimfa-mama [501]

The law of conservation of mass says that matter cannot be created or destroyed by ordinary chemical or physical changes.

This means:

The mass will be the same before and after the chemical or physical change

There are the same number of each type of atom before and after the change

The total mass of all components of a chemical reaction or physical change can be measured before and after the change to demonstrate that the mass is constant.

Scientists believe that energy is conserved, like mass, during a physical or chemical change. The law of conservation of energy says that energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical changes.

Energy can be more challenging for scientists to keep track of during a chemical reaction than mass. Mass is able to be measured on a balance before and after the change, but scientists must use more advanced techniques to measure the energy in a system.

Energy is converted from one form to another during a chemical change.This energy is not created or destroyed; it is just converted from one form of energy to another during the chemical and physical changes that occur.

Physical Change: In a physical change, atoms are rearranged but remain in the same sample of matter. The same numbers of atoms are present before and after the change, and they have the same total mass. Atoms are spread farther apart or pushed closer together during a phase change. When a substance changes phases, the volume may change but the mass doesn't.

Chemical Change: In a chemical change, the original bonds are broken and new bonds are formed. The same atoms are present before and after a chemical change, they are just rearranged to make different compounds.

5 0

3 years ago

Neptunium-237 was the first isotope of a transuranium element to be discovered. the decay constant is /s. what is the half-life

kari74 [83]

The half-life in years of Neptunium-237 which was the first isotope is 2.1 $10^{6}$ years.

Neptunium is most stable and Neptunium-237 is undergoes alpha decay, it means Neptunium-237 is decays by the emission of alpha particles . Seven alpha particles is emitted during decay of Neptunium-237. Neptunium-237 is radioactive actinide elements and first transuranium element.

The transuranium synthesis process involves creating a transuranium element through the transmutation process . The transmutation process is the process of creating heavy elements from light elements. Hence the process is the transmutation of light elements. There are two types: artificial and natural transmutation.

to learn more about transuranium element.

brainly.com/question/1491386

#SPJ4

6 0

2 years ago

Describe a procedure to separate a mixture of sugar black pepper and pebbles

slamgirl [31]

Put the mixture in water, the pebbles will sink, the pepper will float, and the sugar will dissolve

7 0

3 years ago

Coefficient - 2) V205 Subscript for V Subscript for 0 - HELPPP