What is Darwin's name for species that do not appear to have changed for millions of years?

Answer:

I think you should use distillation cauze it helps to separate two mixtures

Answer:

A.) distillation

Explanation:

edge 2021

Answer:

create a plan

the ways of of a student to set a goal

1. Write clear and measurable goals

2.Create a specific plan for each goal

3.Read your goals daily and visualize yourself accomplishing them

4. Reflect yourself to see if you are on target

5. Revise your action plans if needed.

1.)make a plan

2.)make a schedule

5.)pace him or herself

Answer:

pOH = 8.41

Explanation:

From the question given above, we obtained the following information:

Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M

pOH =?

Next, we shall determine the pH of the solution. This can be obtained as follow:

Concentration of Hydrogen ion [H⁺] = 2.6×10¯⁶ M

pH =?

pH = – Log [H⁺]

pH = – Log (2.6×10¯⁶)

pH = 5.59

Finally, we shall determine the pOH of the solution. This can be obtained as follow:

pH = 5.59

pOH =?

pH + pOH = 14

5.59 + pOH = 14

Collect like terms

pOH = 14 – 5.59

pOH = 8.41

Therefore, the pOH of the solution is 8.41

Answer:

8.41

Explanation:

Answer:

See explanation.

Explanation:

Hello!

In this case, since the antacid is usually composed by the following bases:

- Calcium, magnesium and aluminum hydroxides.

- Hydrogen sodium carbonate.

- Sodium carbonate.

In such a way, the feasible reactions that undergo when they react with the stomach acid are shown on the attached picture. As you can see, they all have in common the formation of chlorides and water, which are the neutralization products that calm down the acidity as they are neutral.

Best regards!

Answer:

120.37 g/mol is the molar mass of magnesium sulfate

The question is incomplete, the complete reaction equation is;

The concentration of a hydrogen peroxide solution can be determined by titration

with acidified potassium manganate(VII) solution. In this reaction the hydrogen

peroxide is oxidised to oxygen gas.

A 5.00 cm3 sample of the hydrogen peroxide solution was added to a volumetric flask

and made up to 250 cm3 of aqueous solution. A 25.0 cm3 sample of this diluted

solution was acidified and reacted completely with 24.35 cm3 of 0.0187 mol dm–3

potassium manganate(VII) solution.

Write an equation for the reaction between acidified potassium manganate(VII)

solution and hydrogen peroxide.

Use this equation and the results given to calculate a value for the concentration,

in mol dm–3, of the original hydrogen peroxide solution.

(If you have been unable to write an equation for this reaction you may assume that

3 mol of KMnO4 react with 7 mol of H2O2. This is not the correct reacting ratio.)

Answer:

2.275 M

Explanation:

The equation of the reaction is;

2 MnO4^-(aq) + 16 H^+(aq) + 5H2O2(aq) -------> 2Mn^+(aq) + 10H^+ (aq) + 8H2O(l)

Let;

CA= concentration of MnO4^- =  0.0187 mol dm–3

CB = concentration of H2O2 = ?

VA = volume of MnO4^- = 24.35 cm3

VB = volume of H2O2 = 25.0 cm3

NA = number of moles of  MnO4^- = 2

NB = number of moles of H2O2 = 5

From;

CAVA/CBVB = NA/NB

CAVANB = CBVBNA

CB = CAVANB/VBNA

CB = 0.0187 * 24.35 * 5/25.0 * 2

CB = 0.0455 M

Since  

C1V1 = C2V2

C1 = initial concentration of H2O2 solution = ?

V1 = initial volume of H2O2 solution =  5.0 cm3

C2 = final concentration of H2O2 solution= 0.0455 M

V2 = final volume of H2O2 solution = 250 cm3

C1 = C2V2/V1

C1 = 0.0455 * 250/5

C1 = 2.275 M

Answer:

a. 0.528 M .

Explanation:

Hello!

In this case, since the given by-mass percent can be written as:

[tex]\frac{10gCdSO_4}{100g\ sol}[/tex]

By using the density and molar mass of the solute, cadmium sulfate, we can compute the molarity, by also making sure we convert from mL to L of solution:

[tex]M=\frac{10gCdSO_4}{100g\ sol}*\frac{1molCdSO_4}{208.46gCdSO_4} *\frac{1.10g\ sol}{1mL\ sol}*\frac{1000mL}{1L} \\\\ M=0.528M[/tex]

Thereby, the answer is a. 0.528 M .

Best regards.

The molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.

To calculate molarity we need to find out how many moles of CdSO4 are present in the solution.

Given:

We need to calculate the mass of [tex]CdSO_4[/tex]:

Mass of [tex]CdSO_4[/tex] = (10% / 100%) * Total mass of the solution

Mass of [tex]CdSO_4[/tex] = (10 / 100) * 1000 g (since the volume is 1 L, and the density is 1.10 g/mL)

Mass of [tex]CdSO_4[/tex] =  100 g

So, the number of moles of CdSO4:

Number of moles of [tex]CdSO_4[/tex] = Mass of CdSO4 / Molar mass of CdSO4

Number of moles of [tex]CdSO_4[/tex] = 100 g / 208.46 g/mol

Number of moles of [tex]CdSO_4[/tex] ≈ 0.479 moles

Then, we calculate the molarity of the solution:

Molarity = Number of moles of CdSO4 / Volume of the solution (in liters)

Molarity = 0.479 moles / 1 L

Molarity ≈ 0.479 M

Hence, the molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.

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The question is incomplete, the complete question is;

The compound magnesium nitrate is a strong electrolyte. Write the reaction when magnesium nitrate is put into water:

Answer:

Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)

Explanation:

When we say that a compound is a strong electrolyte, we mean that that the compound dissociates completely in solution to form its ions.

This means that all strong electrolytes attain 100% dissociation of the solid in water according to its stoichiometric equation.

For magnesium nitrate, the reaction equation is;

Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)

Answer:

Name

Sulfur

Atomic Mass

32.066 atomic mass units

Number of Protons

16

Number of Neutrons

16

Number of Electrons

16

Explanation:

Answer:

Explanation:

16 protons

16 electrons

16 neutrons

Answer:

1. nitrous oxide

2. copper sulfide

3. cl2o7

4. MgBr2

Explanation:

hope it helps

Answer:

2. sea level rises sorry if it's wrong

Answer:  B

a chemical change, because a gas is being formed

Explanation:

Answer:

B

Mark Brainliest please

Explanation:

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles =1.500 mole

substituting all the given values in the above equation, we get

number of atoms/molecules=1.500  × 6.022×10²³(Avogadro number)

number of atoms/molecules =9.033×10²³molecules

Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

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Answer:

2875 s

Explanation:

From the question given above, the following data were obtained:

Power (P) = 80 J/s

Energy (E) = 2.3×10⁵ J

Time (t) = ?

Power can simply be defined as the rate at which energy is used. Mathematically, power is expressed as:

Power = Energy / time

P = E/t

With the above formula, we can obtain the time taken for the bulb to consume 2.3×10⁵ J. This can be obtained as follow:

Power (P) = 80 J/s

Energy (E) = 2.3×10⁵ J

Time (t) = ?

Power = Energy / time

P = E/t

80 = 2.3×10⁵ /t

Cross multiply

80 × t = 2.3×10⁵

Divide both side by 80

t = 2.3×10⁵ / 80

t = 2875 s

Therefore, it will take 2875 s for the bulb to consume 2.3×10⁵ J of energy.

Answer:

The correct answer is - 29.45 / 100 x 25.6 = 7.5392 grams

Explanation:

It is given in the question that in 100 gms of CaSO4 there are 29.45 grams of Ca present and there is 25.6 gram of total CaSO4 sample present, So, to calculate the exact value of calcium in this given sample is:

mass of Ca = total amount of sample*percentage of calcium in sample /100

M of Ca =25.6*29.45/100

M of Ca = 7.5392 grams

Thus, the correct procedure is given by 29.45 / 100 x 25.6 = 7.5392 grams

Answer:

Sweets are sold loose, or pre-packed in 120g bags.

The 120 g bags are £1.49 each.

The loose sweets are £0.89 for 100g.

By calculating the price per gram, determine which is better value. Show your working.

Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.

Answer:

Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.

Explanation:

do you like my og name

Energy from Earth’s interior affect surface changes due to:

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Answer and Explanation:

Since the compound sodium nitrate (NaNO₃) is a strong electrolyte, it dissociates completely into ions when is dissolved in water, as follows:

NaNO₃(s) → Na⁺(aq) + NO₃⁻(aq)

So, the solid compound produces the sodium cation (Na⁺) and the nitrate anion (NO₃-) in the aqueous medium.

1. s = 2 m/s

2. d = 130 m

3. t = 7 s

4. d = 56 mi

5.  t = 0.15625 h

6. s = 72 mph

Given

The speed,distance,and time

Required

Units that have not been converted / calculated

Solution

For motion at a constant speed, the formula can be used:

d = v x t or d = s x t

v = velocity

s = speed

1. s = d : t = 40 m : 20 s⇒ s = 2 m/s

2. d = s x t = 13 m/s x 10 s ⇒ d = 130 m

3. t = d : s = 63 m : 9 m/s ⇒ t = 7 s

4.  d = s x t = 28 mph x 2 h ⇒ d = 56 mi

5. t = d : s = 24 mi :  153.6 mph ⇒ t = 0.15625 h

6. s = d : t =1296 mi : 18 h⇒ s = 72 mph

Answer:

C. CaCO3

D. CO2

E. NaCl

. H2O

Answer:

mass of HNO₃ = 0.378 g

Explanation:

Normality = Molarity * number of equivalents

Molarity = Normality/number of equivalents

normality of HNO₃ = 0.30 N, Volume = 20 mL

HNO₃ ionizes in the following way:

HNO₃(aq) ----> H⁺ + NO₃⁻

Therefore, number of equivalents for HNO₃ is 1

molarity of HNO₃ = 0.30/1 =0.30 mol/dm³

Using the formula, molarity = number of moles/volume in liters

number of moles = molarity * volume

Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL

number of moles = 0.006 moles

From the formula, mass = number of moles * molar mass

molar mass of HNO₃ = 63.0 g/mol

mass = 0.006 * 63

mass of HNO₃ = 0.378 g

Answer:

When you heat up water, the water molecules start moving around faster and faster. ... So hot water is less dense than cold water. When you put the two together with the hot water on the bottom, the hot water rises to the top, mixing with the cold water along the way and creating purple water.

Explanation:

have a great day :)

Answer:

im pretty sure its the last one

Explanation:

if plants dont have sun light they will die because the sunlight gives them the nutrients to survive

Answer:

Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.

Explanation:

I hope it's help

Answer:

1.204428 * 10^24 atoms

Explanation:

Number of moles = 2 mol

Number of atoms = ?

The relationship between moles and atoms is given by the avogadro's umber. This is the number of units in one mole of a substance.  The units can be atoms, ions etc In this case it is atoms. The number is equal to  6.02214076 * 10^23

This means;

1 mol = 6.02214076 * 10^23

2 mol = x

Upon solving for x,

x = 2 * 6.02214076 * 10^23

x = 12.04428 * 10^23

x = 1.204428 * 10^24 atoms

Answer:

When an electric charge moves, heat is dissipated due to the drift velocity hence current is induced

Answer: The empirical formula of X  is [tex]Cr_2O_3[/tex]

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of Cr = 68.4 g

Mass of O = 31.5 g

Step 1 : convert given masses into moles.

Moles of Cr =[tex]\frac{\text{ given mass of Cr}}{\text{ molar mass of Cr}}= \frac{68.4g}{52g/mole}=1.31moles[/tex]

Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{31.5g}{16g/mole}=1.97moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Cr = [tex]\frac{1.31}{1.31}=1[/tex]

For O = [tex]\frac{1.97}{1.31}=1.5[/tex]

The simple whole number ratio of Cr : O= 2: 3

Hence the empirical formula is [tex]Cr_2O_3[/tex]

Answer:

2 atm

Explanation:

The symbol 'atm' is used for pressure. Hence, the symbol used to indicate the pressure at which a chemical reaction is carried out can be, 2 atm.