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3 years ago

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A radioactive isotope of potassium (k) has a half-life of 20 minutes. if a 36 gram sample of this isotope is allowed to decay fo

r 80 minutes, how many grams of the radioactive isotope will remain?

1 answer:

lawyer [7]3 years ago

5 0

Fuhhggghhffghhgfghgfdtggggfffffrdd

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HELP HELP HELP ME PLSSSSS 50 POINTS

Anastaziya [24]

Answer:

1) They are the same line so they match equally bc they are measuring the same thing just one is more specific than the other

2) Sonar measures all depths at every possible point and maps it including all the gaps in between the 5cm apart the ocean floor is. The difference between the points could be a cliff or a smooth decline.

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3 years ago

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The least polar bond is found in a molecule of hi hf hcl hbr

mario62 [17]

Answer:

HI is least polar

Explanation:

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3 years ago

Calcium carbonate is often used as an antacid. Your stomach acid is composed of HCl at a pH of 1.5. If you ate toooo much Turkey

stiks02 [169]

<u>Answer:</u> 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

<u>Explanation:</u>

pH is defined as the negative logarithm of hydrogen ion concentration present in the solution

$pH=-\log [H^+]$ .....(1)

Given value of pH = 1.5

Putting values in equation 1:

$1.5=-\log[H^+]$

$[H^+]=10^{(-1.5)}=0.0316M$

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Number of moles of solute}\times 1000}{\text{Volume of solution (mL)}}$ .....(2)

We are given:

Volume of solution = 15.0 mL

Molarity of HCl = 0.0316 M

Putting values in equation 2:

$0.0316=\frac{\text{Moles of HCl}\times 1000}{15.0}\\\\\text{Moles of HCl}=\frac{0.0316\times 15.0}{1000}=4.74\times 10^{-4}mol$

The chemical equation for the reaction of HCl and calcium carbonate follows:

$2HCl+CaCO_3\rightarrow H_2CO_3+CaCl_2$

By the stoichiometry of the reaction:

2 moles of HCl reacts with 1 mole of calcium carbonate

So, $4.74\times 10^{-4}mol$ of HCl will react with = $\frac{1}{2}\times 4.74\times 10^{-4}=2.37\times 10^{-4}mol$ of calcium carbonate

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of calcium carbonate = $2.37\times 10^{-4}mol$

Molar mass of calcium carbonate = 100.01 g/mol

Putting values in the above equation:

$\text{Mass of }CaCO_3=(2.37\times 10^{-4}mol)\times 100.01g/mol\\\\\text{Mass of }CaCO_3=0.0237g$

Hence, 0.0237 g of calcium carbonate would be required to neutralize the given amount of HCl

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2 years ago

Chemists investigated an unknown substance and found it to have the following characteristics:

bija089 [108]

The answer is option C.

That is it is a heterogeneous mixture.

Heterogeneous mixture have the following properties:

1. Different components could be observed in the substance.

2. Different samples of the substance appeared to have different proportions of the components.

3.The components could be easily separated using filters and sorting.

7 0

4 years ago

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What is the IMA of the lever pictured?<br><br><br><br> 0.18<br> 0.20<br> 0.90<br> 5

IceJOKER [234]

<span>The ideal mechanical advantage represents the number of times the input force is multiplied under ideal conditions, that is with no friction. Actual mechanical advantage on the other hand stands for the number of times the input force is multiplied.
Hence; IMA (ideal mechanical advantage)=Le/Lr
The Lr =0.3 +1.2 = 1.5 and Le= 0.3
= 0.3/1.5 = 1/5;
therefore the correct answer is 0.2</span>

6 0

4 years ago

Read 2 more answers