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3 years ago

Why is it important to write a lab report once the experiment is finished?

Chemistry

1 answer:

cluponka [151]3 years ago

5 0

Answer:

Anyone should be able to read the lab report, repeat the experiment, and get the same results. This is important for scientists. ... They help the scientists know what has been done before and how it was performed. This can help them design experiments for their own research

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A chemical equilibrium, the amount of (blank) because( blank)

lianna [129]

Answer:

the amount of product and reactant remains constant because the rates of the foward and reverse reactions are equal

Explanation:

4 0

3 years ago

Calculate the ph of a 0.30 m cocl3 solution. the ka value for co(h2o)63 is 1.0 ✕ 10-5.

astraxan [27]

I think the answer is 5 ??

3 0

3 years ago

How does radiocarbon (or uranium) dating help us better understand the world

navik [9.2K]

Here we have to discuss the understanding of world through radiocarbon or uranium.

The radiocarbon or uranium helps us to determine the age of the world.

All uranium or radiocarbon elements after ejecting the radioactive rays convert to non-radioactive element lead (²⁰⁸Pb). If we assume that during the generation of world there were not any amount of lead was present i.e. only uranium or radiocarbon was present. Then by analysis of any uranium or radiocarbon at the present date one can determine the age of the world as follows:

In present moment we know that the ratio of uranium (U) and lead (Pb) in any uranium ore is 10:3 (gram atom ratio)

So, $\frac{the amount of uranium at the generation of world}{The remaining amount of uranium on present day}$ = $\frac{10+3}{10}$

Therefore, from the equation: ln $\frac{N_{0} }{N}$ = λt (where λ = rate of dissociation of uranium, t = time); we can write:

t = λ⁻¹ ln $\frac{N_{0} }{N}$ = λ⁻¹ln $\frac{13}{10}$ .

On plugging the dissociation rate of uranium we can obtain the age of the world, which is nearly 1.5×10⁹ years.

Thus the use of radioactive element to understand the world is explained.

4 0

3 years ago

A sealed vessel initially contains 100 g of chlorine gas and 90 g of hydrogen gas. The two gases undergo reaction to form HCl. W

EleoNora [17]

Answer:

Explanation:

H2 + Cl2 = 2HCL

From the equation 2g hydrogen combine with 71g of chlorine.

So 35.5 g Cl2 combines with 1g of H2

There are 100g of Cl2 so this will, by proportion, react with 100/35.5 g hydrogen.

This is 2.8 g hydrogen so the mass of HCl formed = 102.8 g.

4 0

3 years ago

A mineral sample is obtained from a region of the country that has high arsenic contamination. An elemental analysis yields the

Gnesinka [82]

Answer:

CaAsHO₄

Explanation:

The data has a mistake in one of the values there. I believe the mistake is on the hydrogen. So, I'm going to assume the value of Hydrogen is 0.6%, so the total percent composition would be 100.1% (Something better). All you have to do is replace the correct value of H (or the value with the mistaken option) and do the same procedure.

Now, to calculate the empirical formula, we can do this in three steps.

Step 1. Calculate the amount in moles of each element.

In these case, we just divide the percent composition with the molar mass of each one of them:

Ca: 22.3 / 40.078 = 0.5564

As: 41.6 / 74.9216 = 0.5552

O: 35.6 / 15.9994 = 2.2251

H: 0.6 / 1.00794 = 0.5953

Now that we have done this, let's calculate the ratio of mole of each of them. This is doing dividing the smallest number of mole between each of the moles there. In this case, the moles of As are the smallest so:

Ca: 0.5564/0.5552 = 1.0022

As: 0.5552/0.5552 = 1

O: 2.2251/0.5552 = 4.0077

H: 0.5953/0.5552 = 1.0722

Now, we round those numbers, and that will give us the number of atoms of each element in the empirical formula

Step 3. Write the empirical formula with the rounded numbers obtained

In this case we will have:

Ca: 1

As: 1

O: 4

H: 1

The empirical formula would have to be:

CaAsHO₄

3 0

3 years ago