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3 years ago

Water boils at 100 °C.

Chemistry

1 answer:

SVETLANKA909090 [29]3 years ago

7 0

Answer:

physical change

Explanation:

there is no change in the water's chemical formula

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What is the purpose of the scientific method? A. To make a guess in order to prove a hypothesis B. To provide a reliable answer

Dafna11 [192]

the is answer d to use an experiment

6 0

3 years ago

Hemoglobin, a protein in red blood cells, carries O2 from the lungs to the body's cells. Iron (as ferrous ion, Fe2+) makes up 0.

levacccp [35]

<u>Answer:</u> The number of $Fe^{2+}$ ions in one molecule of hemoglobin are 4.

<u>Explanation:</u>

According to mole concept:

1 mole of an element contains $6.022\times 10^{23}$ number of atoms.

We are given:

Mass of 1 mole of hemoglobin = $6.8\times 10^4g$

Using above equation:

$6.022\times 10^{23}$ number of molecules have a mass of $6.8\times 10^4g$

So, 1 molecule of hemoglobin will have a mass of $\frac{6.8\times 10^4g}{6.022\times 10^{23}}\times 1=1.129\times 10^{-19}g$

It is also given that 0.33 mass % of hemoglobin has $Fe^{2+}$ ions

So, mass of $Fe^{2+}$ ions will be = $\frac{0.33}{100}\times 1.129\times 10^{-19}g=3.7257\times 10^{-22}g$

To calculate the number of moles, we use the equation:

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

Given mass of iron ion = $3.7257\times 10^{-22}g$

Molar mass of iron ion = 55.85 g/mol

Putting values in above equation, we get:

$\text{Moles of }Fe^{2+}\text{ ion}=\frac{3.7257\times 10^{-22}g}{55.85g/mol}=6.67\times 10^{-24}mol$

Using mole concept:

1 mole of an element contains $6.022\times 10^{23}$ number of atoms.

So, $6.67\times 10^{-24}$ moles of hemoglobin will contain = $6.022\times 10^{23}\times 6.67\times 10^{-24}=4$

Hence, the number of $Fe^{2+}$ ions in one molecule of hemoglobin are 4.

8 0

3 years ago

Match each label below with the appropriate term. Note: there may be more than one correct answer

konstantin123 [22]

Answer:

sigma bond and represent two electrons

7 0

3 years ago

Read 2 more answers

What are the 3 main points of the kinetic molecular theory of gases

tigry1 [53]

Answer:

No energy is gained or lost when molecules collide. The molecules in a gas take up a negligible (able to be ignored) amount of space in relation to the container they occupy. The molecules are in constant, linear motion.

Explanation:

Hope this helps!

5 0

4 years ago

The Ksp of yttrium iodate, Y(IO3)3 , is 1.12×10−10 . Calculate the molar solubility, s , of this compound.

torisob [31]

Answer:

1.427x10^-3mol per L

Explanation:

$Y(IO_{3} )_{3} ---- Y^{3+} +IO_{3} ^{3-}$

I could use ⇌ in the math editor so I used ----

from the question each mole of Y(IO3)3 is dissolved and this is giving us a mole of Y3+ and a mole of IO3^3-

Ksp = [Y^3+][IO3-]^3

So that,

1.12x10^-10 = [S][3S]^3

such that

1.12x10^-10 = 27S^4

the value of s is 0.001427mol per L

= 1.427x10^-3mol per L

so in conclusion

the molar solubility is therefore 1.427x10^-3mol per L

3 0

3 years ago