Who believed that a grain of sand could be divided indefinitely?

What is the name of the compound cs (mno4)2

N76 [4]

D. cadmium permangantie

3 0

3 years ago

If a climate scientist says, "The CO2 concentration in 2018 was 407.4 ppm." What do they mean? *

Alinara [238K]

Answer:

Ppm means the concentration of vapors or gases expressed in parts per million of polluted air.

Explanation:

In Chemistry and Physics, part per million or PPM is a measure that expresses the number of units of a certain existing substance for every million units of the mixture. (Concentration)

In climate the equation is used so:

ppm = parts of polluted air / million parts of air .

ppm = Liters of polluted air / 10∧6 Liters of air.

This is used to find the concentration of gases expressed as parts of gas per million parts of the

polluted air.

In this case, it would be 407.4L of CO2 per 10∧6L of air.

6 0

3 years ago

2 HI(g) ⇄ H2(g) + I2(g) Kc = 0.0156 at 400ºC 0.550 moles of HI are placed in a 2.00 L container and the system is allowed to rea

Alex_Xolod [135]

Answer: The concentration of hydrogen gas at equilibrium is 0.0275 M

Explanation:

Molarity is calculated by using the equation:

$\text{Molarity}=\frac{\text{Number of moles}}{\text{Volume of solution (in L)}}$

Moles of HI = 0.550 moles

Volume of container = 2.00 L

$\text{Initial concentration of HI}=\frac{0.550}{2}=0.275M$

For the given chemical equation:

$2HI(g)\rightleftharpoons H_2(g)+I_2(g)$

Initial: 0.275

At eqllm: 0.275-2x x x

The expression of $K_c$ for above equation follows:

$K_c=\frac{[H_2][I_2]}{[HI]^2}$

We are given:

$K_c=0.0156$

Putting values in above expression, we get:

$0.0156=\frac{x\times x}{(0.275-2x)^2}\\\\x=-0.0458,0.0275$

Neglecting the negative value of 'x' because concentration cannot be negative

So, equilibrium concentration of hydrogen gas = x = 0.0275 M

Hence, the concentration of hydrogen gas at equilibrium is 0.0275 M

4 0

3 years ago

Please,help me in question number 2 and 4. <img src="https://tex.z-dn.net/?f=2and4%20%5C%5C%20" id="TexFormula1" title="2and4

svetoff [14.1K]

I think it’s 890 I really don’t know

8 0

3 years ago

Develop a demonstration to show how weight is not the same thing as mass

maksim [4K]

Answer with Explanation:

"Mass" and "weight" should never be used interchangeably with each other. Mass refers to the total amount of matter that can be measured in an object, while weight refers to the measure of the force of gravity that is acting on the object's mass.

The mass of an object is constant (meaning, it doesn't change even if the object will be placed on another location) while the weight of an object relies on the force of gravity. So, this means that your mass on Earth and on the moon are identical, however, your weight on Earth and on the Moon are different. You will weigh lesser on the Moon because it has a lesser surface gravity than that of Earth.

So, this explains the answer.

4 0

3 years ago