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2 months ago

Guest #952

2 months ago

**Answer:**

The answer is "toxic chemicals".

**Explanation:**

Hydraulic fracture uses compounds such as sand to prevent fractures from closing, chemical additives, and several hundred chemical products, some very toxic and carcinogenic, that perform the function of preventing gas and oil from becoming contaminated. They are also used to prevent corrosion. By depositing fracking liquid waste in the pools, the most volatile products tend to evaporate contributing to air pollution. Some of the elements contained in this wastewater are selenium, radio, and lead.

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Guest #953

2 months ago

When fracking liquid waste is left in pools on the surface, **Toxic Waste or Toxic Chemicals** can evaporate into the air and contribute to pollution. A new study shows that these spills have left surface waters in the area carrying radium, selenium, thallium, lead, and other toxic chemicals that can continue for years at unsafe levels.

Question

PLEASE HELP! I'll mark brainliest! What is the concentration of H+ ions at a pH = 8?
mol/L
What is the concentration of OH– ions at a pH = 8?
mol/L
What is the ratio of H+ ions to OH– ions at a pH = 8?

Solution 1

Acidic and basic are two extremes that describe chemicals, just like hot and cold are two extremes that describe temperature. Mixing acids and bases can cancel out their extreme effects, much like mixing hot and cold water can even out the water temperature. A substance that is neither acidic nor basic is neutral.

The character of acidic, basic and neutral is defined by the concentration of hydrogen ions [H+](mol/L). A solution with a concentration of hydrogen ions higher than 10-7mol/L is acidic, and a solution with a lower concentration is alkaline (another way to say basic). Using the formula, pH=-log[H+], a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. As one can see from this formula, ten times a given concentration of hydrogen ions means one unit lower in terms of pH value (higher acidity), and vice versa.

The formula for ph is given by:pH=−log10[H+]

What is the concentration of H+ ions at a pH = 8?

In calculating for the concentration of hydrogen ion, the formula is given by:[H+]=(10)^(-pH)

Solution:

[H+]=(10)^(-8)**[H+]=0.00000001 mol/L**

What is the concentration of OH– ions at a pH = 8?pH+pOH=148+pOH=14pOH=6

[OH-]=(10)^(-pOH)[OH-]=(10)^(-6)**[OH-]=0.000001**

What is the ratio of H+ ions to OH– ions at a pH = 2?**The ratio is 0.00000001:0.000001 which is equal to 0.01**

The character of acidic, basic and neutral is defined by the concentration of hydrogen ions [H+](mol/L). A solution with a concentration of hydrogen ions higher than 10-7mol/L is acidic, and a solution with a lower concentration is alkaline (another way to say basic). Using the formula, pH=-log[H+], a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. As one can see from this formula, ten times a given concentration of hydrogen ions means one unit lower in terms of pH value (higher acidity), and vice versa.

The formula for ph is given by:pH=−log10[H+]

What is the concentration of H+ ions at a pH = 8?

In calculating for the concentration of hydrogen ion, the formula is given by:[H+]=(10)^(-pH)

Solution:

[H+]=(10)^(-8)

What is the concentration of OH– ions at a pH = 8?pH+pOH=148+pOH=14pOH=6

[OH-]=(10)^(-pOH)[OH-]=(10)^(-6)

What is the ratio of H+ ions to OH– ions at a pH = 2?

Solution 2

**Answer:**

0.00000001

0.000001

0.000001 : 1 or 1 : 100

**Explanation:**

answer on e2020

Question

Which of the following is a way to reduce our total energy use? a) use energy more efficiently
b) get more heat energy from electrical devices
c) increase the amount of fossil fuels we use

Solution 1

A is the right answer

Question

How many moles of Pb(NO3)2 are required if 8 moles of PbCI2 are produced?

Solution 1

PbCl₂ can be synthesized from Pb(NO₃)₂ using various reagents. I will be using HCl as follow,

**Pb(NO₃)₂ + 2 HCl → PbCl₂ + 2 HNO₃**

According to equation,

1 mole of PbCl₂ is formed by = 1 mole of Pb(NO₃)₂

So,

8 moles of PbCl₂ will be produced by = X moles of Pb(NO₃)₂

Solving for X,

X = (8 mol × 1 mol) ÷ 1 mol

X =**8 mol of Pb(NO₃)₂**

Result:

**8 mol of Pb(NO₃)₂ **are required to produce 8 moles of PbCl₂.

According to equation,

1 mole of PbCl₂ is formed by = 1 mole of Pb(NO₃)₂

So,

8 moles of PbCl₂ will be produced by = X moles of Pb(NO₃)₂

Solving for X,

X = (8 mol × 1 mol) ÷ 1 mol

X =

Result:

Question

If a gas is formed when mixing two liquids together why might you not see any bubbles

Solution 1

I'm no chemist, but not every chemical reaction has to bubble. For instance, when you put dry ice in water it creates a mist, but it doesn't make the water bubble.

Question

How is heat transferred through thermal conduction?

Solution 1

Answer:

Heat is transferred through contact between molecules.

Explanation:

a-p-e-x

Solution 2

Thermal conduction was originally called diffusion. Conduction: transfer of heat via direct contact.

Question

Which carbohydrate provides energy for cows but only dietary fiber for humans? A-cellulose
B-starch
C-glycogen
D-sucrose

Solution 1

The answer would be,

A - Cellulose

Take care ^-^

A - Cellulose

Take care ^-^

Solution 2

Starch serves energy for cows and diets withhold many starches

Question

Water is sometimes removed from the products of a reaction by placing the products in a closed container with excess P4O10. Water is absorbed by the following reaction. P4O10 + 6H2O es001-1.jpg 4H3PO4 What is the mole ratio of water to H3PO4? Do not simplify the ratio. Hes001-2.jpgO:Hes001-3.jpgPOes001-4.jpg = :4

Solution 1

H2O:H3PO4 = 6:4.

I just took the test and got it right!

I just took the test and got it right!

Solution 2

Answer : **The correct answer for mole ratio of H₂O : H₃PO₄ = 6: 4 .**

Mole ratio :

It is defined as mole of one substance to another substance in a balanced reaction . In the balanced reaction , the coefficient written before the substances are taken as moles of that substance.

The given balanced reaction between P₄H₁₀ and H₂O is :

P₄O₁₀ + 6 H₂O → 4 H₃PO₄

Mole of H₂O = 6

Mole of H₃PO₄ = 4

**Hence mole ratio of Water : H₃PO₄ = 6 : 4 **

Question

A 98.0°C piece of cadmium (c=.850J/g°C) is placed in 150.0g of 37.0°C water. After sitting for a few minutes, both have a temperature of 38.6°C. What was the mass of the cadmium sample?

Solution 1

The answer is **19.9 grams** cadmium.

Assuming there was no heat leaked from the system, the heat q lost by cadmium would be equal to the heat gained by the water:

heat lost by cadmium = heat gained by the water

-qcadmium = qwater

Since q is equal to mcΔT, we can now calculate for the mass m of the cadmium sample:

-qcadmium = qwater

-(mcadmium)(0.850J/g°C)(38.6°C-98.0°C)) = 150.0g(4.18J/g°C)(38.6°C-37.0°C)

mcadmium = 19.9 grams

Assuming there was no heat leaked from the system, the heat q lost by cadmium would be equal to the heat gained by the water:

heat lost by cadmium = heat gained by the water

-qcadmium = qwater

Since q is equal to mcΔT, we can now calculate for the mass m of the cadmium sample:

-qcadmium = qwater

-(mcadmium)(0.850J/g°C)(38.6°C-98.0°C)) = 150.0g(4.18J/g°C)(38.6°C-37.0°C)

mcadmium = 19.9 grams

Question

Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride? a.mg + 2 hcl → h2 + mgcl2
b.mg + hcl → h + mgcl
c.2 mg + 6 hcl → 3 h2 + 2 mgcl2
d.mg + 2 hcl → 2 h + mgcl2
e.mg + 3 hcl → 3 h + mgcl2?

Solution 1

Answer is: a. Mg + 2HCl → H₂ + MgCl₂.

Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.

Oxidation half reaction: Mg⁰ → Mg²⁺ + 2e⁻.

In this chemical reaction, magnesium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).

Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.

Oxidation half reaction: Mg⁰ → Mg²⁺ + 2e⁻.

In this chemical reaction, magnesium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).

Question

What is the melting point of a solution in which 3.5 grams of sodium chloride is added to 230 mL of water?

Solution 1

We are going to use this equation:

ΔT = - i m Kf

when m is the molality of a solution

i = 2

and ΔT is the change in melting point = T2- 0 °C

and Kf is cryoscopic constant = 1.86C/m

now we need to calculate the molality so we have to get the moles of NaCl first:

moles of NaCl = mass / molar mass

= 3.5 g / 58.44

= 0.0599 moles

when the density of water = 1 g / mL and the volume =230 L

∴ the mass of water = 1 g * 230 mL = 230 g = 0.23Kg

now we can get the molality = moles NaCl / Kg water

=0.0599moles/0.23Kg

= 0.26 m

∴T2-0 = - 2 * 0.26 *1.86

**∴T2 = -0.967 °C**

ΔT = - i m Kf

when m is the molality of a solution

i = 2

and ΔT is the change in melting point = T2- 0 °C

and Kf is cryoscopic constant = 1.86C/m

now we need to calculate the molality so we have to get the moles of NaCl first:

moles of NaCl = mass / molar mass

= 3.5 g / 58.44

= 0.0599 moles

when the density of water = 1 g / mL and the volume =230 L

∴ the mass of water = 1 g * 230 mL = 230 g = 0.23Kg

now we can get the molality = moles NaCl / Kg water

=0.0599moles/0.23Kg

= 0.26 m

∴T2-0 = - 2 * 0.26 *1.86

Solution 2

**Answer:**

0.952 °C

**Explanation:**

The change in melting point is computed as:

ΔT = k*m*i

where ΔT is the difference between the melting point of water and of solution, k is a constant (1.86 °C*kg/mol for water), i is the van't Hoff factor (equal to 2 for sodium chloride because 2 ions are obtained after its dissolution), and m is the molality of the solution.

Molar mass of sodium chloride: 58.44 g/mol

Moles of of sodium chloride: mass / molar mass 3.5/58.44 = 0.059 mol

Density of water 1 kg/L

230 mL of water are equivalent to 0.23 L

mass of water: density * volume = 1*0.23 = 0.23 kg

Molality of the solution: m = moles of solute/ kg of solvent = 0.059/0.23 = 0.256

Finally:

ΔT = 1.86*0.256*2 = 0.952 °C

Water melting point: 0 °C

So, the solution melting point is: 0 - 0.952 = 0.952 °C

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