what's the answer to this question

kkknskndcnndcks

a

Answer:

Explanation:

Answer:

pH change is -0.07

Explanation:

Using H-H equation for acetic acid:

pH = pKa + log [Acetate salt] / [Acetic acid]

Replacing:

pH = 4.74 + log[1.188M] / [1.188M]

pH = 4.74

The HCl reacts with sodium acetate producing acetic acid, thus:

HCl + CH₃COONa → CH₃COOH + NaCl

That means the final moles of sodium acetate are initial moles - moles of HCl and moles of acetic acid are initial moles + moles of HCl.

As the volume of the buffer is 1.0L, initial moles of both substances are 1.188moles. After reaction, the moles are:

sodium acetate: 1.188mol - 0.1mol = 1.088mol

Acetic acid: 1.188mol + 0.1mol = 1.288mol

Using again H-H equation:

pH = 4.74 + log[1.088M] / [1.288M]

pH = 4.67

pH change is: 4.67 - 4.74 = -0.07

The correct answer is C. The water is the solvent because the green pellets dissolved in it.

Explanation:

In solutions, the are two substances involved, the solvent and the solute. The solvent is usually a liquid substance; additionally, the solvent dissolves another substance, which is known as the solute. For example, if you dissolve a spoon of salt in a glass of water, the solute is the salt which is the substance dissolved and the solvent is the water because the solute is dissolved in it. According to this, in the case presented the water is the solvent because the green pellets which are the solute dissolve in it.

Answer: The equilibrium constant for the reaction is 0.000016.

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric coefficients.

The given balanced equilibrium reaction is,

                            [tex]2NOCl(g)\rightleftharpoons 2NO(g)+Cl_2(g)[/tex]

The expression for equilibrium constant for this reaction will be,

[tex]K_c=\frac{[NO]^2[Cl_2]}{[NOCl]^2}[/tex]

Now put all the given values in this expression, we get :

[tex]K_c=\frac{(1.2\times 10^{-3})^2\times (2.2\times 10^{-3})}{(1.4\times 10^{-2})^2}[/tex]

[tex]K_c=0.000016[/tex]

Thus the equilibrium constant for the reaction is 0.000016.

Answer:

The correct option is B

b. Phosphorylation by a kinase using ATP (which turns the complex off) and dephosphorylation by a phosphatase (which turns the complex on).

Explanation:

The pyruvate dehydrogenase complex is described as a complex having many enzymes that catalyse decarboxylation of pyruvate by oxidation to yield NADH and acetyl‐CoA, which makes the influx of acetyl-coA from glycolysis to increase into the Krebs cycle.

It can be found in the mitochondrial matrix and pyruvate which is conveyed through enzyme Pyruvate Translocase to PDH complex.

Regulation of pyruvate dehydrogenase complex occured through allosteric effectors as well as phosphorylation.the main regulatory processes controlling pyruvate dehydrogenase's activity in eukaryotes such as plants and animals Phosphorylation is by a kinase using ATP which first turns the complex off and the later dephosphorylation by a phosphatase which turns the complex on

Answer: 32 mol HCI

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

[tex]Molarity=\frac{n}{V_s}[/tex]

where,

n = moles of solute

[tex]V_s[/tex] = volume of solution in Liters

Now put all the given values in the formula of molarity, we get

[tex]4.0M=\frac{moles}{8.0L}[/tex]

[tex]moles={4.0M\times 8.0L}=32mol[/tex]

Therefore, the moles of HCI needed to prepare 8.0 liters of a 4.0 M solution of HCI are 32.

Answer:

0.533 M KOH

Explanation:

                        2 KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2 H20 (l}

from reaction   2 mol            1 mol

                           x                  15*10^(-3)*0.425 mol        

15.00 mL = 15*10^(-3)L H2SO4 solution

15*10^(-3)L*0.425 mol/L = 15*10^(-3)*0.425 mol H2SO4

x =2*15*10^(-3)*0.425/1 = 2*15*10^(-3)*0.425 mol KOH

23.9mL = 23.9 *10^(-3) L KOH

M(KOH)  - molarity  KOH

M(KOH)*V(KOH solution) = M(KOH)*23.9 *10^(-3) L KOH - is moles KOH

2*15*10^(-3)*0.425 mol H2SO4 = M(KOH)*23.9 *10^(-3) L KOH

M(KOH) = 2*15*10^(-3)*0.425 /(23.9 *10^(-3)) = 0.533 M

Answer: D=8.27 g/cm³

Explanation:

Density is mass/volume. Mass is in grams and volume is in liters. In this case, the problem wants our volume to be in cm³. All we need to do is to make some conversions to convert kg/m³ to g/cm³.

[tex]D=\frac{38.3kg}{0.00463m^3} *\frac{(1m)^3}{(100cm)^3} *\frac{1000g}{1kg}[/tex]

With this equation, the m³ and kg cancel out, and we are left with g/cm³.

D=8.27 g/cm³

Answer:

B) THE DEPTH OF THE LAKE IS 0.060 m

Explanation:

b) Determine the depth of the lake in metres

1. Using the general gas law, we will calculate the initial pressure of the air bubbles.

P1V1 /T1 = P2V2/T2

P1 = Unknown

T1 = 5.24 °C

T2 = 18.73 °C

P2 = 0.973 atm

V1 = V1

V2 = 6V1

P1 = P2 V2 T1 / V1 T2

P1 = 0.973 * 6V1 * 5.24 / V1 * 18.73

P1 = 5.09852 * 6 / 18.73

P1 = 30.59112 / 18.73

P1 = 1.633 atm.

2. Calculate the depth of the lake:

             Pressure = length * density * acceleration

            length = Pressure / density * acceleration

Pressure = 1.633 atm = 1.633 * 101, 325 Nm^2 = 165, 463.725 Nm^2

Density =  1.02 g/cm3 = 1.02 * 10^3 kg/m^3

Acceleration = 9.8 m/s^2

So therefore, the length in metres is:

Length = density * acceleration / pressure

Length =  1.02 *10^3 * 9.8 / 165, 463.725  

Length = 9.996 * 10^3 / 165 463.725

Length = 0.06 m

Hence, the depth of the lake is 0.06 m

Answer:

18.7887 g of NaCl

Explanation:

The question reads - How many grams of NaCl will be produced from 18.0 g of Na and 23.0 g of Cl2?

Let us start by writing out the balanced equation of the reaction:

Na + Cl2 ---> NaCl2

1 mole, each of Na and Cl2 is required to produce 1 mole of NaCl.

mole = mass/molar mass

Therefore

18 g of Na = 18/23 = 0.7826 mole

23 g of Cl2 = 23/71 = 0.3239 mole

In this case, the Na is in excess and the Cl2 becomes the limiting reagent. Hence

0.3239 mole of Cl2 will react with 0.3239 mole of Na to yield 0.3239 mole of NaCl.

mass of 0.3239 mole NaCl = 0.3239 x 58 = 18.7887 g

Hence, 18.7887  grams of NaCl will be produced from 18.0 g of Na and 23.0 g of Cl2.

Answer:

Solids have a definite shape and volume. Liquids have a definite volume, but take the shape of the container. Gases have no definite shape or volume.

Explanation:

Answer:

Liquids properties include retention of volume and its conformation to the shape of its container. The  

particles in a liquid have more kinetic energy than the particles in the corresponding solid. Solids are  

structurally rigid and resist changing shape or volume. Solid particles have the least amount of kinetic  

energy. Properties of gas include easily compressible, the expand to fill their container and they occupy  

more space than a solid or liquid. Gas particles have the most amount of kinetic energy

Explanation:

Answer:the answer is DI

Explanation:APΣX

ANSWER: From experience and observation, the pathogen that responds more faster to treatments are PARASITES.

This is because, our body are already used to parasite, as they feed and mostly live inside our body. Parasites becomes harmful to our body, when it is allowed to be much in the body, thereby weakening the immune system of the body. Intake of vaccination reduces the number of parasites in the body, which gives the immune system the chance of recovering and protecting the body.

Parasite does not replicate more faster like viruses and other pathogens. These makes it more easier for treatment to work more faster. They are also easily killed by taking the proper treatment, and the rate of their replications are very slow when compared to the rate of their death when vaccinated.

Some example disease caused by parasites are:

1) Giardiasis

2) Trichomoniasis

3) Malaria

4) Toxoplasmosis

5) Intestinal worms

6) Pubic lice

All this disease above responds very fast to medical treatment, unless when they is complications, which are mostly when the parasite has been allowed to cause more harm and replicate much in the body, without any treatment. This is why doctors advice patients that lives at the tropical regions to periodically vaccinate themselves on parasitic infections.

Answer: Yes

Explanation: Since strong acids react with and use up water molecules, and strong bases do not

Answer:

Lead

Explanation:

Lead (Pb) has atomic number 82

Ex Polonium (Po) has atomic number 84 and mass number 212

Answer:

lead

Explanation:

Answer:

The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol

Explanation:

The ∆H (heat of reaction) of the combustion reaction is the heat that accompanies the entire reaction. For its calculation you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient (number of molecules of each compound that participates in the reaction) and finally subtract them:

Enthalpy of the reaction= ΔH = ∑Hproducts - ∑Hreactants

In this case, you have:  2 NOCl(g) → 2 NO(g) + Cl₂(g)

So, ΔH=[tex]2*H_{NO} +H_{Cl_{2} }-2*H_{NOCl}[/tex]

Knowing:

Replacing:

75.5 kJ/mol=2* 90.25 kJ/mol + 0 - [tex]H_{NOCl}[/tex]

Solving

-[tex]H_{NOCl}[/tex]=75.5 kJ/mol - 2*90.25 kJ/mol

-[tex]H_{NOCl}[/tex]=-105 kJ/mol

[tex]H_{NOCl}[/tex]=105 kJ/mol

The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol

Answer:

0.102 M

Explanation:

Given data

Step 1: Calculate the moles of solute

The molar mass of sucrose is 342.3 g/mol. The moles corresponding to 35.0 g of sucrose are:

[tex]35.0g \times \frac{1mol}{342.3g} =0.102mol[/tex]

Step 2: Calculate the molarity of sucrose in the solution

The molarity is equal to the moles of solute divided by the liters of solution.

[tex]M=\frac{0.102mol}{1.000L} =0.102 M[/tex]

Answer:

10

Explanation:

The 5 will multiply the subscript 2 on the K atoms making it 10

Answer:

C6H6 < C7H15OH < C6H13OH < C2H5OH

Explanation:

Hello,

In this case, since the organic molecules solubility is defined in terms of the presence of hydrogen bonds as intermolecular forces, which are formed between oxygen and hydrogen and the length of the organic chain, we can notice that hydroxyl-containing longer chains tend to be less water soluble whereas shorter chains more soluble as the polar part of the chain will lead the solubility. In addition to it, chains with lack of oxygen tend to be highly water insoluble. Therefore, we can notice that C6H6 is the least water soluble, next C7H15OH, then C6H13OH and the most soluble is C2H5OH.

Best regards.

Answer:

Sodium hydroxide

Out of the two substances, sodium hydroxide would you use to unclog the pipes.

Sodium hydroxide is used to produce soaps, rayon, paper, products that explode, dyes, and petroleum products.

The presence of sodium hydroxide in a cleanser or in a homemade aqueous solution converts these pesky fats into soaps and the soap is then easily removed by water.

Hence, out of the two substances, sodium hydroxide would you use to unclog the pipes.

Learn more about sodium hydroxide here:

brainly.com/question/20892971

#SPJ2

Explanation:

It is given that,

Dimension of a solid block of substance is 74.0 cm by 55.0 cm by 29.0 cm

Mass of solid block is 625 kg or 625000 grams

We need to find the density of solution. The mass per unit its volume is called density.

[tex]\rho=\dfrac{m}{V}\\\\\rho=\dfrac{625000}{74\times 5\times 29}\\\\\rho=58.24\ g/cm^3[/tex]

So, the density of solid block is [tex]58.24\ g/cm^3[/tex]. The density of water is [tex]1\ g/cm^3[/tex]. The density of block is more than water. Hence, it will sink.

Answer:

THE AMOUNT OF THE SAMPLE REMAINING AFTER 5 HOURS IS 1250 CPM

Explanation:

A sample has a half life of 100 minutes. To solve for the amount remaining after a given amount of 10000CPM decay in 5 hours, we use the formula:

Nt = No * (1/2)^t/t1/2

Where:

Nt = amount remaining = unknown

No = initial amount = 10000 CPM

t = time elapsed for decay = 5 hours = 60*5minutes = 300 minutes

t1/2 = half life = 100 minutes

Putting the values into the formula, we have:

Nt = 10000 * (1/2)^ 300/100

Nt = 10000 * (1/2)^3

Nt = 10000 * 0.125

Nt = 1250 CPM

The amount of the sample remaining after 5 hours is 1250 CPM.

Answer:

substituting unsaturated fats—like those found in olive oil—for saturated fats could lower your chance of developing heart disease. 

Answer:

  6.0221409e+23

Explanation:

The number of molecules in a mole of any substance is Avogadro's number, 6.0221409e+23.

Answer:

1.00 M

Explanation:

Step 1: Write the balanced equation

HBr + LiOH ⇒ LiBr + H₂O

Step 2: Calculate the reacting moles of lithium hydroxide

40.00 mL of 0.500 M solution react. The reacting moles of LiOH are:

[tex]40.00 \times 10^{-3} L \times \frac{0.500mol}{L} = 0.0200 mol[/tex]

Step 3: Calculate the reacting moles of hydrobromic acid

The molar ratio of HBr to LiOH is 1:1. The reacting moles of hydrobromic acid are 1/1 × 0.0200 mol = 0.0200 mol.

Step 4: Calculate the molarity of hydrobromic acid

0.0200 moles of HBr are in 20.00 mL of the solution. The molarity of the hydrobromic acid solution is:

[tex]M= \frac{0.0200 mol}{20.00 \times 10^{-3} L } =1.00 M[/tex]

Answer:

(PH color chart at the bottom)

Chop the cabbage into small pieces until you have about 2 cups of chopped cabbage. Place the cabbage in a large beaker or other glass container and add boiling water to cover the cabbage. Allow at least 10 minutes for the color to leach out of the cabbage. Alternatively, you can place about 2 cups of cabbage in a blender, cover it with boiling water, and blend it.

Filter out the plant material to obtain a red-purple-bluish colored liquid. This liquid is at about pH 7. The exact color you get depends on the pH of the water.

Pour about 50–100 mL of your red cabbage indicator into each 250 mL beaker.

Add various household solutions to your indicator until it changes color. Use separate containers for each household solution—you don't want to mix chemicals that don't go well together.

2=Red

4=Purple

6=Violet

8=Blue

10=Blue Green

12 = Green Yellow