Which of the following are parts of the excretory system? *

hram777 [196]

All of the above answers are true right answer is option D

because, no bond no molecule no interaction no life,

no bond= only element will exist

Energy would not exist coz energy consumption and excretion takes place during bond formation and bond breaking process!

3 0

3 years ago

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Assuming the volumes are additive, what is the [Cl−] in a solution obtained by mixing 297 mL of 0.675 M KCl and 664 mL of 0.338

Elden [556K]

<u>Answer:</u> The concentration of chloride ions in the solution obtained is 0.674 M

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

<u>For KCl:</u>

Molarity of KCl solution = 0.675 M

Volume of solution = 297 mL

Putting values in equation 1, we get:

$0.675=\frac{\text{Moles of KCl}\times 1000}{297}\\\\\text{Moles of KCl}=\frac{(0.675mol/L\times 297)}{1000}=0.200mol$

1 mole of KCl produces 1 mole of chloride ions and 1 mole of potassium ion

Moles of chloride ions in KCl = 0.200 moles

<u>For magnesium chloride:</u>

Molarity of magnesium chloride solution = 0.338 M

Volume of solution = 664 mL

Putting values in equation 1, we get:

$0.338=\frac{\text{Moles of }MgCl_2\times 1000}{664}\\\\\text{Moles of }MgCl_2=\frac{(0.338mol/L\times 664)}{1000}=0.224mol$

1 mole of magnesium chloride produces 2 moles of chloride ions and 1 mole of magnesium ion

Moles of chloride ions in magnesium chloride = $(2\times 0.224)=0.448mol$

Calculating the chloride ion concentration, we use equation 1:

Total moles of chloride ions in the solution = (0.200 + 0.448) moles = 0.648 moles

Total volume of the solution = (297 + 664) mL = 961 mL

Putting values in equation 1, we get:

$\text{Concentration of chloride ions}=\frac{0.648mol\times 1000}{961}\\\\\text{Concentration of chloride ions}=0.674M$

Hence, the concentration of chloride ions in the solution obtained is 0.674 M

5 0

2 years ago

Which of the following contains a nonpolar covalent bond? O2 CO NaCI HF

jasenka [17]

Answer: The nonpolar covalent bond happens in an O₂ molecule.

Explanation: Nonpolar bonds happen where there's no difference between the polarity of the atoms involved. This usually happens when the same atoms bond to each other, which explains why the O₂ molecule is the one who has this bond.

5 0

3 years ago

(6.022*10^23)*2.58=<br> what’s the answer

Sladkaya [172]

The answer would be
$1.553676 \times {10}^{24}$

8 0

3 years ago

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A solution was found to have a 15.6 % transmittance at 500 nm, its wavelength of maximum absorption, using a cell with a path le

Gnesinka [82]

For the absorbance of the solution in a 1.00 cm cell at 500 nm is mathematically given as

A’ = 0.16138

<h3>What is the absorbance of the solution in a 1.00 cm cell at 500 nm?</h3>

Absorbance (A) 2 – log (%T) = 2 – log (15.6) = 0.8069

Generally, the equation for the Beer’s law is mathematically given as

A = ε*c*l

0.8069 = ε*c*(5.00 )

ε*c = 0.16138 cm-1

then for when ε*c is constant

l’ = 1.00

A’ = (0.16138 cm-1)*(1.00 cm)

A’ = 0.16138

In conclusion, the absorbance of the solution in a 1.00 cm cell at 500 nm is

A’ = 0.16138