Please help with this question

Answer:A

Explanation: The universe is always expanding at all times. It dosnt expand that much though, very little

Answer:

all of they above

Explanation:

Answer:

One of water's most significant properties is that it takes a lot of heat to it to make it get hot. Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C.

Explanation:

Answer:

KCrO₃

Explanation:

26.6% K, 35.3% Cr and 33.0% O

The steps in obtaining the empirical formulae from percentage composition is given as;

Step 1:

Divide the percentage composition by the atomic mass of the elements

K = 26.6 / 39.0983  = 0.6803

Cr = 35.3 / 51.9961 = 0.6789

O = 33.0 / 16  = 2.0625

Step 2:

Divide all though by the smallest number (0.6789)

K = 0.6803 / 0.6789 = 1.002

Cr = 0.6789 / 0.6789 = 1

O = 2.0625 / 0.6789 = 3.038

The Empirical formular is the ratio between the elements. This given as;

KCrO₃

Answer:

the veins and arteries are the things that distribute blood throughout your body. There was a lot more blood in the arteries, that's making them very important and should not be cut ever. Veins on the other hand can be cut but you should still not cut them to begin with as if to not lose any blood. They distribute blood throughout your body that comes from your heart and helps muscles skeletal another systems of your body work.

Answer:

The number following the name of the element is the number of subatomic particles inside the nucleus of the atom. This means that it is the mass number of the isotope. The average atomic mass of the element is the sum of the products of the percentage abundance and mass number of the naturally occurring isotopes.

Since, the average atomic mass of the hydrogen is nearest to 1 then, the most abundant isotope should be hydrogen-1.

Answer:

Answer:

wala hindi ko yan alam ty

Answer:

A. "All molecules are compounds, but not all compounds are molecules"

Explanation:

An example of a compound-molecule is oxygen. The elemenal is O, because the periodic table isn't describing molecules, it's describing atoms. The molecule is O2 because it takes 2 O atoms to make a molecule of oxygen.

The primary difference between a molecule and a compound is 'compounds must be composed of more than one type of atom​'.

Explanation:

So, from this, we can conclude that the primary difference between a molecule and a compound is 'compounds must be composed of more than one type of atom​'.

Learn more about molecules and compounds here:

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Answer:

In the ring of fire

Hope this acc helps

Answer:

linear angleee

Explanation:

lol i dont know what to put here

Answer:

B) Bent

There are a lot of types of bents but this one is linear bent.

Answer:

(K) = [H2] [Cl2]  /  [HCl]²

Explanation:

The equation of the reaction is given as;

2 HCl (g)  ⇔ H2 (g) + Cl2 (g)

The Equilibrium constant is the ratio of the concentration of the products and reactants raised to the power of their coefficients

Products =  H2 and Cl2

Reactants =  HCl

Equilibrium constant (K) = [H2] [Cl2]  /  [HCl]²

Answer:

0.0125 moles of NaOH are present

Explanation:

Molarity, M, is an unit of concentration widely used in chemistry. Is defined as the ratio between moles of solute (In this case, NaOH) and liters of solution.

250.0mL are = 0.250L of solution. As the molarity of the solution is 0.05M = 0.05moles / 1L, the moles present are:

0.250L * (0.05moles / 1L) =

Answer:

1. A. 9 eggs

2. B. 5:3

3. C. Exactly 44 g

4. C. Mass and atoms only

5. D. 6.81 g of PH₃

6. C. 88.4%

7. B. O₂

8. D. 30.8 g CO₂

9. B.

10. B.

11. C. 99 g

12. D. mole ratio

13. C. Theoretical

14. A. 6.0 mol H₂O

15. D. 39.7 g CH₃OH

16. A. 650 g HgO

17. D. 8.8 mol H₂

18. B. 82.6%

Explanation:

1. The number of eggs it takes to make 1 cake = 3 eggs

The number of eggs it takes to make 3 × 1 = 3 cake = 3 × 3 = 9 eggs

Therefore, the correct option is;

A. 9 eggs

2. The given reaction is presented as follows;

C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)

In the above reaction, we have;

Moles of , O₂, reacted = 5 moles

Moles of , CO₂, produced = 3 moles

The ratio of the of O₂ reacted to moles of CO₂ produced = 5 moles:3 moles

∴ The ratio of the of O₂ reacted to moles of CO₂ produced = 5:3

The correct option is;

B. 5:3

3. The reaction is presented as follows;

O₂ (g) + C(s) → CO₂ (g)

From the reaction, 1 mole (12 g) of carbon produces 1 mole of CO₂

The molar mass of CO₂ = The mass of 1 mole of CO₂ = 44.01 g/mol

Given that the reaction is completed, the mass of CO₂ produced = The mass of 1 mole of CO₂ ≈ 44 g

The correct option is;

C. Exactly 44 g

4. The given reaction is presented as follows;

N₂ + 3 F₂ → 2NF₃

The initial number of atom = 2 + 6 = 8

The final number of atom = 2 × 4   = 8

∴ The initial number of atom = The final number of atom

Therefore, the number of atoms is conserved;

The mass of the reactants ≈ 28 g/mol + 3 × 37.996806 g/mol ≈ 141.993612 g/mol ≈ 142 g/mol

The mass of the product ≈ 2 × 71 g.mol = 142 g/mol

∴ The mass is conserved

Moles of reactants = 1 + 3 = 4

Moles of products = 2

∴ The number of moles is not conserved

The correct option is

C. Mass and atoms only

5. The molar mass of P₄ = 123.895048 g/mol

One mole of P₄ (123.895048 g) produces four moles (4 × 34.00) of PH₃

6.20 g of P₄. will produce (4 × 34.00)/(123.895048) × 6.20 g ≈ 6.80576 g ≈ 6.81 g

The correct option is D. 6.81 g of PH₃

6. The percentage yield = ((The actual yield)/(The ideal yield)) × 100

The actual yield of silver = 38.1 g

The ideal yield of silver = 43.1 g

∴ The percentage yield = ((38.1 g)/(43.1 g)) × 100 = 88.3990719258% ≈ 88.4%

The percentage yield = 88.4%

The correct option is C. 88.4%

7. The given chemical equation is presented as follows;

CS₂ (g) + 3 O₂ (g) → CO₂ (g) + 2 SO₂ (g)

The number of moles in 192 g of O₂ = 192 g/(32 g/mol) = 6 moles

Given that 3 moles of O₂ reacts with 1 mole of CS₂ to produce 1 mole of CO₂ and 2 moles SO₂,  therefore 2 × 3 = 6 moles of O₂ will reacts with 2 × 1 = 2 moles of CS₂ to produce 2 moles of CO₂ and 4 moles SO₂

∴ The limiting reactant is;

B. O₂

8. The given chemical equation is presented as follows;

2 C₈H₁₈ (g) + 25 O₂ (g) → 16 CO₂ (g) + 18 H₂O (l)

The number of moles in 10 g of C₈H₁₈, n₁ = (10 g)/(114.26 g/mol)

The number of moles of CO₂ produced, n₂ = (10 g)/(114.26 g/mol) × 16/2 ≈ 0.7 moles

The mass of CO₂ produced, m ≈ 44.01 × n₂ ≈ 44.01 g/mol × 0.7 moles ≈ 30.807 grams ≈ 30.8 grams

The theoretical yield of CO₂ from completely burning 10.0 g of C₈H₁₈ ≈ 30.8 grams of CO₂

The correct option is D. 30.8 g CO₂

9. The correct option is B. The limiting reactants determine the maximum amount of product that can be formed

10. Option B, which has 3 atoms of each element combining to form a product with 1 atom of one element and 2 atoms of the other element

The correct option is B.

11. By the conservation of mass, we have;

The mass of the reactants = The mass of the products

Let 'x' represent the mass of zinc in the products of the reaction

Therefore, we have;

61 g of calcium + 207 g of zinc chloride = 169 g of calcium chloride + x g of Zinc

∴  x g = 61 g + 207 g - 169 g = 99 g

The mass of zinc in the products of the reaction, x g = 99 g

The correct option is;

C. 99 g

12. The quantity that must be used to convert from one chemical substance to another is the mole ratio

The correct option is D. mole ratio

13. The maximum mass of the product that could form in a reaction is called the theoretical yield, which is option C.

The correct option is C. Theoretical

14. 1 mole of O₂ produces 2 moles of water (H₂O), therefore;

3 × 1 = 3.0 moles of O₂ will produce 3 × 2 = 6 moles of H₂O

The correct option is

A. 6.0 mol H₂O

15. 2 mole × 2.02 g/mol = 4.04 g of H₂ (g) produces 32.05 g CH₃OH (l)

∴ 5 g of H₂ (g) will produce 32.05 g × 5/4.04 ≈ 39.6658416 g ≈ 39.7 g of CH₃OH

The correct option is;

D. 39.7 g CH₃OH

16. 2 (2 × 216.59 g = 433.18 g) moles of HgO produces 1 mole of O₂

1.5 mole of O₂ will be produced by 1.5 × 2 = 3 moles (3 × 216.59 g = 649.77 g ≈ 650 g) of HgO

The correct option is A 650 g HgO

17. 3 moles of H₂ produces 2 moles of NH₃

The number of moles of NH₃ in 100 g of NH₃, n = 100 g/(17.04 g/mol) = 5.868544 moles

The number of moles of H₂ that will produce 5.868544 moles of NH₃ = 3/2 × 5.868544 moles = 8.802816 moles ≈ 8.8 moles

Therefore, the correct option is;

D. 8.8 mol H₂

18. The theoretical yield of PbO = (223.2/331.2) × 9.90 g = 6.67173913 g

The percentage yield = (5.51 g)/(6.67173913 g) × 100 ≈ 82.6%

The correct option is option B 82.6%.

Answer:

Usually, the cells are round, elongated or spherical. There are also some cells which are long and pointed on both the ends. Such cells exhibit spindle shape. In some cases, the cells are very long.

Explanation:

Hope I helped! Brainliest plz!

Answer:

a: 6 moles

b: 6.75 moles

c: 5 grams

Explanation:

a: mole ratio 2:3

b: mole ratio 2:3

c: mole ratio 2:2

Answer:

A force meter

Explanation:

This can be fixed by multiplying the product contacting nitrogen by 2. o The new chemical equation is N2 +H2 →2 NH3. Reactants. Products. Nitrogen. 2. 2.

Answer:

Anhydrous sodium carbonate is stable to heat and does not decompose even when it is heated to redness. This is because sodium carbonate salt on heating with acids react to release carbon dioxide.

Air that is less dense Speeds up, while air that is more dense Slows Down.

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Answer and Explanation:

2 mol of Fe(OH)3 produces 1 mol of Fe2(SO4)3  then 2.1 mol of Fe(OH)3 will produce (1)/(2) x 2.01 = 1.05 mol of Fe2(SO4)3  amount of H2O = (6)/(2) * 2.01 = 6.03 mol HO2