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3 years ago

How many moles of calcium atoms are in each mole of calcium carbonate?

Chemistry

1 answer:

Tanya [424]3 years ago

5 0

Answer:

The number of moles of calcium atom in each mole of calcium carbonate is 1 mole of calcium atoms

Explanation:

The chemical formula for CaCO₃ = 100.086 g

The number of molecules in one mole of a substance is given by the Avogadro's number, $N_A$ = 6.022 × 10²³ molecules

The number of calcium atoms in one molecule of CaCO₃ = 1 atom of calcium

Therefore, the number of calcium atoms in 1 mole of CaCO₃ = 1 × 6.022 × 10²³ atoms of calcium = 6.022 × 10²³ atoms of calcium

6.022 × 10²³ atoms of calcium = The number of toms in 1 mole of calcium atoms

Therefore, the number of moles of calcium atom in each mole of calcium carbonate = 1 mole of calcium atoms.

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Which compound has both ionic and covalent bonding?.

Nikitich [7]

Answer: Calcium carbonate is another example of a compound with both ionic and covalent bonds. Here calcium acts as the cation, with the carbonate species as the anion. These species share an ionic bond, while the carbon and oxygen atoms in carbonate are covalently bonded

Explanation:

4 0

3 years ago

When a strong acid is titrated with a strong base using phenolphthalein, the color changes suddenly at the end point. The color

larisa86 [58]

Answer:

Keto - enol tautomerism

Explanation:

Phenolphthalein is an organic molecule (formula: C20H14O4), which is used in to determine the final volume in an acid-base titration, this is, as the molecule changes from one to another color, depending on the Ph of the solution (in acids solution, the molecule remains colorless, while in basics solutions it remains pink) :

The molecule of phenolphthalein is a week acid, which losses a proton (H+) when it´s in solution: the undissociated molecule is colorless, while the correspondent anion (without a H+) is pink. This may be simplified with the following reaction:

H₃In⁺ ⇄ H₂In (colorless) ⇄ In⁻² (pink) ⇄ In(OH) ⁻³

- When adding a base (for example, NaOH) to phenolphthalein (initially, a colorless solution), molecule losses one H⁺ and we obtain In⁻², which is pink

- When adding an acid, the original structured is recovered, so color turns from pink to colorless

This change color is not only explained with adding an acid or a base, but also with phenolphthalein structure, that leads to a keto-enol tautomerism: as molecule has 2 hydroxyl groups (- OH) and 1 carbonyl group (C = O), compounds with this structure have an equilibrium between both groups:

R1 = C H– OH ⇄ R1 – C = O

With this change, phenolphthalein structure changes and hence, color solution changes as well

4 0

3 years ago

A gas diffuses 1/6 times faster than hydrogen gas (H2). What is the molar mass of the gas? 59.95 g/mol 66.54 g/mol 68.68 g/mol 7

taurus [48]

Solution us here,

let the rate of diffusion of H2(r1) be x and⁷ the rate of diffusion of gas(r2) be x+x/6=7x/6.

Molar mass of H2 (M1)=2 g

Molar mass of gas(M2)= ?

Now, from the Ghram's law of diffusion of gas,

$\frac{r1}{r2} = \sqrt{ \frac{m2}{m1} } \\ or \: \frac{x}{ \frac{7x}{6} } = \sqrt{ \frac{m2}{2} } \\ or \: \frac{6}{7} = \sqrt{ \frac{m2}{2} } \\ squaring \: in \: both \: sides \\ \frac{36}{49} = \frac{m2}{2} \\ or m2 = 1 .469$

here, it looks like I have done wrong.

But all of the answers in option are wrong.

Because, rate of diffusion of any gas is inversely proportional to the square root of its malor mass.

And in the question, gas has higher rate of diffusion than hrdrogen. So it should have molar mass less than hydrogen.

8 0

4 years ago

Read 2 more answers

Hydrazine (N2H4) is used as rocket fuel. It reacts with oxygen to form nitrogen and water.

Marina86 [1]

Answer:

See explanation below for answers

Explanation:

This is a stochiometry reaction. LEt's write the overall reaction again:

N₂H₄ + O₂ ---------> N₂ + 2H₂O

This reaction is taking place at Standard temperature and pressure conditions (STP) which are P = 1 atm and T = 273 K. To know the volume of N₂ formed, we need to know first how many moles are formed, and this can be calculated with the reagents and the limiting reagent. Let's calculate the moles first of the reagents:

MM N₂H₄ = 32 g/mol; MM O₂ = 32 g/mol

mol N₂H₄ = 2000 / 32 = 62.5 moles

mol O₂ ? 2100 / 32 = 65.63 moles

Now that we have the moles, we need to apply the stochiometry and calculate the limiting reagent. According to the overall reaction we have a mole ratio of 1:1 between N₂H₄ and O₂, therefore:

1 mole N₂H₄ ---------> 1 mole O₂

62.5 moles ----------> X

X = 62.5 moles of O₂

But we have 65.63 moles, therefore, the limiting reactant is the N₂H₄.

We also have a 1:1 mole ratio with the N₂, so:

moles N₂H₄ = moles N₂ = 62.5 moles

Now that we have the moles, we can calculate the volume with the ideal gas equation:

PV = nRT

V = nRT / P

R: gas constant (0.082 L atm / K mol)

Replacing we have:

v = 62.5 * 0.082 * 273 / 1

V = 1399.13 L of N₂

Now, how many grams of the excess remains?, we know how many moles are reacting so, let's see how much is left:

moles remaining = 65.63 - 62.5 = 3.12 moles

then the mass of oxygen:

m = 3.12 * 32 = 100.16 g of O₂

7 0

3 years ago

Read 2 more answers

Calculate the pH of a 0.10 M HCN solution that is 0.0070% ionized.

Anastaziya [24]

Answer:

D) 5.15

Explanation:

Step 1: Write the equation for the dissociation of HCN

HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)

Step 2: Calculate [H⁺] at equilibrium

The percent of ionization (α%) is equal to the concentration of one ion at the equilibrium divided by the initial concentration of the acid times 100%.

α% = [H⁺]eq / [HCN]₀ × 100%

[H⁺]eq = α%/100% × [HCN]₀

[H⁺]eq = 0.0070%/100% × 0.10 M

[H⁺]eq = 7.0 × 10⁻⁶ M

Step 3: Calculate the pH

pH = -log [H⁺] = -log 7.0 × 10⁻⁶ = 5.15

7 0

3 years ago