74g of Ca(OH)2 (74 g/mol) in 340 ml solution

Answer:

(a) pH=4.0

(b) pH=8.3

Explanation:

Hello there!

In this case, since the pH is understood as the potential of the hydrogen in an aqueous solution, and we can calculate it is as follows:

[tex]pH=-log([H^+])[/tex]

We simply need to plug in the concentrations on each question as shown below:

(a)

[tex]pH=-log(1x10^{-4})\\\\pH=4[/tex]

(b)

[tex]pH=-log(5x10^{-9})\\\\pH=8.3[/tex]

Regards!

Answer:

[tex]m_{Fe_2O_3}=549gFe_2O_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction for this problem about stoichiometry:

[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]

Whereas there is a 3:2 mole ratio of oxygen (molar mass = 32.0 g/mol) to iron (III) oxide (molar mass = 159.69 g/mol) and therefore, the correct stoichiometric setup is:

[tex]m_{Fe_2O_3}=165gO_2*\frac{1molO_2}{32.00gO_2}*\frac{2molFe_2O_3}{3molO_2} *\frac{159.69gFe_2O_3}{1molFe_2O_3} \\\\m_{Fe_2O_3}=549gFe_2O_3[/tex]

Regards!

Answer:

D: Increase of pressure

Answer:

1.03 M

Explanation:

Step 1: Write the balanced equation

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the reacting moles of HCl

30.0 mL (0.0300 L) of 0.500 M HCl react.

0.0300 L × 0.500 mol/L = 0.0150 mol

Step 3: Calculate the moles of NaOH that react with 0.0150 moles of HCl

The molar ratio of NaOH to HCl is 1:1. The moles of NaOH that react are 1/1 × 0.0150 mol = 0.0150 mol.

Step 4: Calculate the molar concentration of NaOH

0.0150 moles of NaOH are in 14.5 mL (0.0145 L).

M = 0.0150 mol/0.0145 L = 1.03 M

Answer:

The correct answer is - A. Ethanol reduces air pollution.

Explanation:

Ethanol is believed to be better fuel for the environment than other petroleum fuels. Ethanol emits lower carbon dioxide as it is clean smokeless fuel, and produces less or the same oxides of nitrogen and hydrocarbons.

It is produced by the process of fermentation of molasses by yeast. Mixing it with the other fuels is found to be CO2 reduces by 30% of emissions to the atmosphere.

Answer:

8 meters per second per second

Explanation:

Newton's second law: [tex]f=ma[/tex], force = mass multiplied by acceleration.

Therefore 56 / 7 = acceleration = 8

The answer should be sex cell.

Explanation:

Answer: the answer is A

Explanation:

Answer:

The answer to your question is, A. consumer.

Explanation:

Any organism that 'consumes' other organisms is a consumer

Answer: As a result an increase in kinetic energy also happens.

Explanation:

Potential energy is the energy occupied by an object or substance due to its position.

Kinetic energy is the energy occupied by an object of substance due to its motion.

If the kinetic and potential energy in a system are equal and then an increase in potential energy will occur.

As a  result, there will also occur an increase in kinetic energy also.

Thus, we can conclude that as a result an increase in kinetic energy also happens.

Answer:

1. A

2. C

3. B

4. D

5. D

6. B

Explanation:

I'm not quiet sure on 5 but I'm pretty sure its correct

Explanation:

Steaming up or fogging happens when steam condenses on the mirror. Steam emerging from hot water can condense on a colder surface. That’s the reason you can see the result on a mirror instantaneously. Obviously, for a bathroom mirror to steam up, the steam that originates at the shower spray (or the bathtub) has to travel through the cooler air to reach the mirror. Since air tends to heat up easily, the mirror can steam up fast.

The reactant necessary for a combustion reaction is oxygen.

(option D).

Combustion is a chemical reaction that occurs when a substance reacts with oxygen, producing heat and light. In order for combustion to take place, three elements are needed: fuel, heat, and oxygen.
Fuel is the substance that undergoes combustion, such as gasoline, wood, or methane. Heat is the energy required to initiate and sustain the reaction. Lastly, oxygen is the reactant that combines with the fuel, allowing it to burn and release energy.
When a combustion reaction occurs, the fuel and oxygen combine to form carbon dioxide (option C) and water (option A). This process is exothermic, meaning it releases energy in the form of heat and light.
For example, when wood is burned in the presence of oxygen, it undergoes combustion. The heat from a match or a spark provides the necessary activation energy to start the reaction. Oxygen from the air combines with the carbon in the wood, producing carbon dioxide and releasing energy in the form of heat and light.
In summary, oxygen is the reactant necessary for a combustion reaction. It combines with the fuel and releases energy in the form of heat and light.

(option D).

For more such questions on combustion reaction

https://brainly.com/question/13251946

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Answer:

Atomic nuclei would fly apart

Explanation:

Answer:

B). The smallest part of matter still retaining chemical properties.

Answer:

your answer for that problem is 34.5

Answer:

Acoustic survey data can help inform scientists about the locations of the rainforest with the highest biodiversity. ... By working with these companies, The Nature Conservancy can help inform them of where they might try to create wildlife corridors or connected habitats on their lands

Answer:

The volume of the gas is approximately 4.41 liters

Explanation:

The details of the data of the Neon gas are;

The number of moles of Neon gas present, n = 11.6 moles

The temperature of the sample of Neon gas, T = 120 K

The pressure of the sample of the Neon gas, P = 25.6 atm

By the ideal gas equation, we have;

P·V = n·R·T

Where;

R = The universal gal constant = 0.08205 L·atm·mol⁻¹·K⁻¹

Therefore, we get;

V = n·R·T/P

Which gives;

V = 11.6 moles × 0.08205 L·atm·mol⁻¹·K⁻¹ × 120 K/(25.9 atm) ≈ 4.4097915 L

The volume of the gas, V ≈ 4.41 L.

Answer:

0.333J/g°C is the specific heat of the metal

Explanation:

The heat that the metaal gives is equal to the heat that water is absorbing. The equation is:

S(metal)*ΔT(metal)*Mass(metal) = S(H2O)*ΔT(H2O)*Mass(H2O)

Where S is specific heat, ΔT is change in temperature and mass the mass in grams of the metal and water.

Replacing:

S(metal)*(100.0°C-27.2°C)*125.0g = 4.184J/g°C*(27.2°C-24.3°C)*250.0g

S(metal) = 4.184J/g°C*(27.2°C-24.3°C)*250.0g / (100.0°C-27.2°C)*125.0g

S(metal) = 0.333J/g°C is the specific heat of the metal

Answer:

V2 = 159.48 mL

Explanation:

Given the following data;

Initial volume = 200 mL

Initial temperature = 28°C

Final temperature = -33°C

To find the final volume, V2, we would use Charles law;

First of all, we would convert the temperature in Celsius to Kelvin.

Mathematically, it is given by the formula;

Kelvin = 273 + C

Substituting into the equation, we have;

Initial temperature, T1:

Kelvin = 273 + 28

Kelvin = 301K

Initial temperature, T1:

Kelvin = 273 - 33

Kelvin = 240K

To find new volume V2, we would use Charles' law.

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles is given by;

[tex] VT = K[/tex]

[tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Where;

V1 and V2 represents the initial and final volumes respectively.

T1 and T2 represents the initial and final temperatures respectively.

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

Making V2 as the subject formula, we have;

[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]

[tex] V_{2}= \frac{200}{301} * 240[/tex]

[tex] V_{2}= 0.6645 * 240 [/tex]

V2 = 159.48 mL

[tex]methane \: reacts \: with \: oxygen [/tex]

CH4 + 2O2 → CO2 + 2H2O.

Step-by-step explanation

L.H.S.

C = 1, H = 4, O = 2×2 = 4.

R.H.S

C = 1, O = 2, H = 2×2= 4, O = 2.

Answer:

20

Explanation:

not sure please correct me if im wrong

Answer:

20

Explanation:

Got it right on time 4 learning

Answer:

Evolution in the broadest sense explains that what we see today is different from what existed in the past. Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.Something that happened in the past is thus not "off limits" for scientific study. Hypotheses can be made about such phenomena, and these hypotheses can be tested and can lead to solid conclusions. Furthermore, many key aspects of evolution occur in relatively short periods that can be observed directly—such as the evolution in bacteria of resistance to antibiotics.Laws, like facts and theories, can change with better data. But theories do not develop into laws with the accumulation of evidence. Rather, theories are the goal of science.

Explanation:

Answer:

Clean a platinum or nichrome (a nickel-chromium alloy) wire by dipping it into concentrated hydrochloric acid and then holding it in a hot Bunsen flame. Repeat this until the wire produces no color in the flame.