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3 years ago

Structures in the human body work together to perform specific functions. The

Chemistry

2 answers:

Delicious77 [7]3 years ago

6 0

The answer is D= tissue

Nesterboy [21]3 years ago

5 0

D. tissue

The organisation is as follows:

Cell - Tissue - Organ - Organ system - Organism

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The proof that ch4 is a weak acid

boyakko [2]

Answer: because ch4 is not considered a acid they said it is too weak

Explanation:

8 0

3 years ago

Read 2 more answers

A solution of HNO3 has a [H+] concentration of 0.001 M. What is the pH of point

Citrus2011 [14]

Answer:

Explanation:

pH=-log(H+)

- Hope that helps! Please let me know if you need further explanation.

7 0

3 years ago

A chemist must prepare 300.0mL of nitric acid solution with a pH of 0.70 at 25°C. He will do this in three steps: Fill a 300.0mL

d1i1m1o1n [39]

<u>Answer:</u> The volume of concentrated solution required is 9.95 mL

<u>Explanation:</u>

To calculate the pH of the solution, we use the equation:

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

We are given:

pH = 0.70

Putting values in above equation, we get:

$0.70=-\log[H^+]$

$[H^+]=10^{-0.70}=0.199M$

1 mole of nitric acid produces 1 mole of hydrogen ions and 1 mole of nitrate ions.

Molarity of nitric acid = 0.199 M

To calculate the volume of the concentrated solution, we use the equation:

$M_1V_1=M_2V_2$

where,

$M_1\text{ and }V_1$ are the molarity and volume of the concentrated nitric acid solution

$M_2\text{ and }V_2$ are the molarity and volume of diluted nitric acid solution

We are given:

$M_1=7.0M\\V_1=?mL\\M_2=0.199M\\V_2=350mL$

Putting values in above equation, we get:

$7.0\times V_1=0.199\times 350.0\\\\V_1=\frac{0.199\times 350}{7.0}=9.95mL$

Hence, the volume of concentrated solution required is 9.95 mL

6 0

3 years ago

Two equilibrium reactions of nitrogen with oxygen, with their corresponding equilibrium constants (Kc) at a certain temperature,

7nadin3 [17]

Answer:

Kc = 1.54e - 31 / 2.61e - 24

Explanation:

1 ) $N_{2}(gas) + O_{2}(gas)\rightarrow 2NO(gas)$ ; Kc = 1.54e - 31

2) $N_{2}(gas) + 1/2O_{2}(gas)\rightarrow N_{2}O(gas)$ ; Kc = 2.16e - 24

upon reversing ( 2 ) equation

$N_{2}O(gas)\rightarrow N_{2}(gas) + 1/2O_{2}(gas)$ Kc = 1/2.16e - 24

now adding 1 and reversed equation (2)

$N_{2}(gas) + O_{2}(gas)\rightarrow 2NO(gas)$

$N_{2}O(gas)\rightarrow N_{2}(gas) + 1/2O_{2}(gas)$

we get ,

$N_{2}O(gas) + 1/2O_{2}(gas)\rightarrow 2NO(gas)$ Kc = 1.54e-31 × 1/2.61e - 24

equilibrium constant of equation (3) is -

Kc = 1.54e - 31 / 2.61e - 24

3 0

3 years ago

Osmosis is the process responsible for carrying nutrients and water from groundwater supplies to the upper parts of trees. The o

Nady [450]

Answer:

0.825 M

Explanation:

The osmotic pressure is a colligative property, that can be calculated using the following expression.

π = M × R × T

where,

π is the osmotic pressure

M is the molarity

R is the ideal gas constant

T is the absolute temperature (24°C + 273 = 297 K)

M = π / R × T = 20.1 atm / (0.08206 atm.L/mol.K) × 297 K = 0.825 M

5 0

3 years ago