You have just won a block of pure 24-carat gold. Have you just procured an element, compound, or mixture?

Una solución formada por 58 gramos de cloruro de sodio (NaCl) en 100 mL de solución posee una concentración

masya89 [10]

Answer:

58

Explanation:

8 0

4 years ago

A chemist prepares a sample of helium gas at a certain pressure, temperature and volume and then removes all but a fourth of the

cupoosta [38]

Answer:

The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.

Explanation:

Pressure in the container is P and volume is V.

Temperature of the helium gas molecules = $T_1$

Molecules helium gas = x

Moles of helium has = $n_1= \frac{x}{N_A}$

PV = nRT (Ideal gas equation)

$PV=n_1RT_1$ ...[1]

After removal of helium gas only a fourth of the gas molecules remains and pressure in the container and volume should remain same.

Molecules of helium left after removal = $\frac{x}{4}$

Moles of helium has left after removal = $n_2= \frac{x}{4\times N_A}$

$PV=n_2RT_2$ ...[2]

$n_1RT_1=n_2RT_2$

$\frac{x}{N_A}\times T_1=\frac{x}{4\times N_A}\times T_2$

$T_1=\frac{T_2}{4}$

$T_2=4T_1$

The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.

6 0

4 years ago

What are the rules for writing

Alborosie

Answer:

When naming molecular compounds prefixes are used to dictate the number of a given element present in the compound. ” Mono-” indicates one, “Di-” indicates two, “Tri-” is three, “Tetra-” is four, “Penta-” is five, and “Hexa-” is six, “Hepta-” is seven, “Octo-” is eight, “Nona-” is nine, and “Deca-” is ten.

6 0

3 years ago

Compare the modern (electron cloud) model of the atom with Bohr’s atomic model. Which of these statements describe the two model

AfilCa [17]

Answer:

B. Bohr’s model electrons cannot exist between orbits, but in the electron cloud model, the location of the electrons cannot be predicted.

AND

C. The modern model explains all available data about atoms; Bohr’s model does not.

Explanation:

The answers are right on Edge. :)

6 0

3 years ago

Read 2 more answers

Breathing equipment used by rescue workers needs to capture the CO2 the humans breath out and produce O2 for them to breath in,

const2013 [10]

Answer: $4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2$

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for reaction of potassium superoxide with carbon dioxide to produce oxygen and potassium carbonate will be:

$4KO_2+2CO_2\rightarrow 2K_2CO_3+3O_2$

8 0

3 years ago