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3 years ago

What is an indication that a lake is healthy?

Chemistry

2 answers:

N76 [4]3 years ago

7 0

Answer:

Explanation:

As bioindicators are the organism that indicate or monitor the health of the environment

Inessa [10]3 years ago

5 0

Answer:

is D

Explanation:

You might be interested in

Write the chemical equation for...

Mamont248 [21]

Balanced reaction is given by

Ca+2H_2O—»Ca(OH)_2+H_2

On both sides

Ca=1
O=2
H=4

Hence balanced

7 0

2 years ago

66.667 mL of 3.000 M H2SO4 (aq) solution was neutralized by the stoichiometric amount of 4.000 M Al(OH)3 solution in a coffee cu

Alik [6]

Answer:

$\large \boxed{\Delta_{\textbf{r}}H =\text{-4600 J$\cdot$ mol}^{-1}}$

Explanation:

This is an unrealistic problem, because Al(OH)₃is highly insoluble in water.

There are two parts to this question:

A. Stoichiometry — in which we figure out the volumes, masses, and moles of products

B. Calorimetry — in which we calculate the enthalpy of reaction.

A. Stoichiometry

1. Calculate the volume of Al(OH)₃

(a) Balanced chemical equation.

2Al(OH)₃ + 3H₂SO₄ ⟶ Al₂(SO₄)₃+ 6H₂O

V/mL: 66.667

c/mol·L⁻¹: 4.000 3 .000

(b) Moles of H₂SO₄

$\rm \text{66.667 mL H$_{2}$}SO_{4} \times \dfrac{\text{3.000 mmol H$_{2}$SO}_{4}}{\text{1 mL H$_{2}$SO}_{4}} = \text{200.00 mmol H$_{2}$SO}_{4}$

(c). Moles of Al(OH)₃

The molar ratio is 2 mmol Al(OH)₃:3 mmol H₂SO₄

$\text{Moles of Al(OH)}_{3} = \text{200.00 mmol of H$_{2}$SO}_{4} \times \dfrac{\text{2 mmol Al(OH)}_{3}}{\text{3 mmol H$_{2}$SO}_{4}}\\\\= \text{133.33 mmol Al(OH)}_{3}$

(d). Volume of Al(OH)₃

$\text{Moles of Al(OH)}_{3} = \text{200.00 mmol of H$_{2}$SO}_{4} \times \dfrac{\text{1 mL Al(OH)}_{3}}{\text{4 mmol H$_{2}$SO}_{4}} = \text{50.000 mL Al(OH)}_{3}$

B. Calorimetry

There are two energy flows in this reaction.

q₁ = heat from reaction

q₂ = heat to warm calorimeter

q₁ + q₂ = 0

nΔH + mCΔT = 0

Data:

Moles of Al₂(SO₄)₃ = 0.066 667 mol

C = 1.10 J°C⁻¹g⁻¹

T_i = 22.3 °C

T_f = 24.7 °C

Calculations

(a) Mass of solution

Assume the solutions have the same density as water (unrealistic).

Mass of sulfuric acid solution = 66.667 g

Mass of aluminium hydroxide solution = <u> 50.000 </u>

TOTAL = 116.667 g

(b) ΔT

ΔT = T_f - Ti = 24.7 °C - 22.3 °C = 2.4°C

(c) ΔH

$\begin{array}{ccccl}n\Delta H & +& mC \Delta T& = &0\\\text{0.066 667 mol }\times \Delta H& + & \text{116.667 g} \times 1.10 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$} \times 2.4 \, ^{\circ}\text{C} & = & 0\\0.066667 \Delta H \text{ mol} & + & \text{310 J} & = & 0\\&&0.066667 \Delta H \text{ mol} & = & \text{-310 J} & & \\\end{array}\\$

$\begin{array}{ccccl}& &\Delta H & = & \dfrac{\text{-310 J}}{\text{0.066667 mol}}\\\\& &\Delta H & = & \textbf{-4600 kJ/mol}\\\end{array}\\\large \boxed{\mathbf{\Delta_{\textbf{r}}H} =\textbf{-4600 J$\cdot$ mol}^{\mathbf{-1}}}$

This is an absurd answer, but it's what comes from your numbers.

6 0

3 years ago

The term "accuracy" BEST refers to which of the following?

Hatshy [7]

It is , how close a measurement is to an accepted value for the measurement !

Rate this the brainliest, Thank Youuu !

8 0

3 years ago

A solution is prepared from 8 grams of acetic acid (CH2CO2H) and 725 grams of water. What is the molarity of this solution?

Andrews [41]

Hello!

First, we can assume the density of water to be 1 g/mL, so the volume of water would be 725 mL. The density of Acetic Acid (Pure) is 1,05 g/mL so 8 grams would represent 7,61 mL

Now we can apply the following conversion factor to calculate the molarity of the solution, using the molar mass of Acetic Acid:

$[CH_3CO_2H]=\frac{8 g_{CH_3CO_2H} }{725 mL + 7,61 mL}* \frac{1000 mL}{1 L}* \frac{1 mol_{CH_3CO_2H} }{60,05 g_{CH_3CO_2H} }$

$[CH_3CO_2H]=0,1818 M$

So, the concentration of acetic acid would be 0,1818 M

Have a nice day!

4 0

4 years ago

Read 2 more answers

What does an atom contain?

netineya [11]

Answer:

neutron, proton, and electrons

Explanation:

The protons and the neutrons make up the center of an atom which is called the nucleus

7 0

3 years ago