All categories

2 years ago

Help Please!!

Chemistry

1 answer:

Ivahew [28]2 years ago

7 0

The first answer would be:

Measure the sequence of events on earth over time.

I believe the second answer would be:

The age of earth. ( I say this because geological time is used to describe timing and the relationship of events in earths history)

I’m not sure about number 3 but I hope this was somewhat useful!!

You might be interested in

The conversion of co2 and h2o into organic compounds using energy from light is called

Fed [463]

The answer you're looking for is photosynthesis

3 0

3 years ago

Find the pH of a 0.100 molar H2C6O6 solution with ka, where KA is equal 8.0×10–5

lubasha [3.4K]

The pH of the solution is 2.54.

Explanation:

pH is the measure of acidity of the solution and Ka is the dissociation constant. Dissociation constant is the measure of concentration of hydrogen ion donated to the solution.

The solution of C₆H₂O₆ will get dissociated as C₆HO₆ and H+ ions. So the molar concentration of 0.1 M is present at the initial stage. Lets consider that the concentration of hydrogen ion released as x and the same amount of the base ion will also be released.

So the dissociation constant Kₐ can be written as the ratio of concentration of products to the concentration of reactants. As the concentration of reactants is given as 0.1 M and the concentration of products is considered as x for both hydrogen and base ion. Then the

$K_{a}=\frac{[H^{+}][HB] }{[reactant]}$

[HB] is the concentration of base.

$8 * 10^{-5} =\frac{x^{2} }{0.1}\\\\\\x^{2} = 8 * 10^{-5}*0.1$

$x^{2} = 0.08 * 10^{-4}\\ \\x = 0.283*10^{-2}$

Then

$pH = - log [x] = - log [ 0.283 * 10^{-2}]\\ \\pH = 2 + 0.548 = 2.54$

So the pH of the solution is 2.54.

4 0

3 years ago

How many moles are in 7.1x10^21 atoms of iron?

Nitella [24]

Answer:

0.011 moles

Explanation:

There are about 6.02*10^23 atoms in a mole, so in the given sample, there are

$\frac{7.01 \times {10}^{21} }{6.02 \times {10}^{23} }$

which is about 0.011 moles.

8 0

2 years ago

What would be the advantage of using a net ionic equation to represent a redox reaction

wolverine [178]

The net ionic equation is shorter to use and already leaves out the electrons that transferred from the reducing agent to the oxidizing agent. Also, in some occasions the aqueous ions H+ and (or) OH- ions that help balance the net ionic charge are no longer shown in the net ionic equation.

5 0

3 years ago

I need help with this

Lelechka [254]

Answer:

The answer is its equal to the volume of its container.

--------------------------------------------------------------------------------

I hope this helps! :)

7 0

3 years ago