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3 years ago

How many moles of KNO3 are in 500 mL of 2.0 M KNO3? ___ mol KNO3

Chemistry

2 answers:

Step2247 [10]3 years ago

5 0

Answer:

It's 1. I just did it on edg

weeeeeb [17]3 years ago

4 0

Answer: 1mole

Explanation:

Mole = concentration× Volume (dm3)

Mole = 2× 500/1000

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In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4 (g) 2O2

Degger [83]

Answer:

The energy released will be -94.56 kJ or -94.6 kJ.

Explanation:

The molar mass of methane is 16g/mol

The given reaction is:

$CH_{4}(g) + 2O_{2} (g) --> CO_{2} (g)+ 2H_{2}O(l)$

the enthalpy of reaction is given as ΔH = -890.0 kJ

This means that when one mole of methane undergoes combustion it gives this much of energy.

Now as given that the amount of methane combusted = 1.70g

The energy released will be:

$=\frac{energy released by one moleXgiven mass}{molarmass} =\frac{-890X1.7}{16}= -94.56 kJ$

7 0

3 years ago

In the laboratory a student combines 26.2 mL of a 0.234 M chromium(III) acetate solution with 10.7 mL of a 0.461 M chromium(III)

Natalka [10]

<u>Answer:</u> The molarity of $Cr^{3+}$ ions in the solution is 0.299 M

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

<u>For chromium (III) acetate:</u>

Molarity of chromium (III) acetate solution = 0.234 M

Volume of solution = 26.2 mL

Putting values in equation 1, we get:

$0.234=\frac{\text{Moles of chromium (III) acetate}\times 1000}{26.2}\\\\\text{Moles of chromium (III) acetate}=\frac{0.234\times 26.2}{1000}=0.00613mol$

1 mole of chromium (III) acetate $(Cr(CH_3COO)_3)$ produces 1 mole of chromium $(Cr^{3+})$ ions and 3 moles of acetate $(CH_3COO^-)$ ions

Moles of $Cr^{3+}\text{ ions}=(1\times 0.00613)=0.00613moles$

<u>For chromium (III) nitrate:</u>

Molarity of chromium (III) nitrate solution = 0.461 M

Volume of solution = 10.7 mL

Putting values in equation 1, we get:

$0.461=\frac{\text{Moles of chromium (III) nitrate}\times 1000}{10.7}\\\\\text{Moles of chromium (III) nitrate}=\frac{0.461\times 10.7}{1000}=0.00493mol$

1 mole of chromium (III) nitrate $(Cr(NO_3)_3)$ produces 1 mole of chromium $(Cr^{3+})$ ions and 3 moles of nitrate $(NO_3^-)$ ions

Moles of $Cr^{3+}\text{ ions}=(1\times 0.00493)=0.00493moles$

<u>For chromium cation:</u>

Total moles of chromium cations = [0.00613 + 0.00493] = 0.01106 moles

Total volume of solution = [26.2 + 10.7] = 36.9 mL

Putting values in equation 1, we get:

$\text{Molarity of }Cr^{3+}\text{ cations}=\frac{0.01106\times 1000}{36.9}\\\\\text{Molarity of }Cr^{3+}\text{ cations}=0.299M/tex]Hence, the molarity of [tex]Cr^{3+}$ ions in the solution is 0.299 M

5 0

3 years ago

Complete ionic,net and spectator ions for the following

yawa3891 [41]

Answer:

Explanation:

1) ZnBr₂ (aq) + AgNO₃ (aq)

Chemical equation:

ZnBr₂ (aq) + AgNO₃ (aq) →Zn(NO₃)₂(aq) + AgBr(s)

Balanced chemical equation:

ZnBr₂ (aq) + 2AgNO₃ (aq) →Zn(NO₃)₂(aq) + 2AgBr(s)

Ionic equation:

Zn²⁺(aq) + Br₂²⁻ (aq) + 2Ag⁺ (aq)+ 2NO⁻₃ (aq) → Zn²⁺(aq) +(NO₃)₂²⁻(aq) + 2AgBr(s)

Net ionic equation:

Br₂²⁻ (aq) + 2Ag⁺ (aq) → 2AgBr(s)

The Zn²⁺((aq) and NO⁻₃ (aq) are spectator ions that's why these are not written in net ionic equation. The AgBr can not be splitted into ions because it is present in solid form.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.

2) Ca(OH)₂ (aq) + Na₂SO₄ (aq)

Chemical equation:

Ca(OH)₂ (aq) + Na₂SO₄ (aq) → CaSO₄(s) + NaOH(aq)

Balanced chemical equation:

Ca(OH)₂ (aq) + Na₂SO₄ (aq) → CaSO₄(s) + 2NaOH(aq)

Ionic equation:

Ca²⁺(aq) + OH₂²⁻ (aq) + 2Na⁺(aq) + SO₄²⁻ (aq) → CaSO₄(s) + 2Na⁺(aq) + 2OH⁻ (aq)

Net ionic equation:

Ca²⁺(aq) + SO₄²⁻ (aq) → CaSO₄(s)

The OH⁻ ((aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The CaSO₄ can not be splitted into ions because it is present in solid form.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.

3) Al(NO₃)₃ (aq) + Na₃PO₄ (aq)

Chemical equation:

Al(NO₃)₃ (aq) + Na₃PO₄ (aq) → Al(PO₄)(s) + NaNO₃ (aq)

Balanced chemical equation:

Al(NO₃)₃ (aq) + Na₃PO₄ (aq) → Al(PO₄)(s) + 3NaNO₃ (aq)

Ionic equation:

Al³⁺(aq) + 3NO⁻₃ (aq) + 3Na⁺(aq) + PO₄³⁻ (aq) → Al(PO₄)(s) + 3Na⁺(aq) + NO⁻₃ (aq)

Net ionic equation:

Al³⁺(aq) + PO₄³⁻ (aq) → Al(PO₄)(s)

The Na⁺((aq) and NO⁻₃ (aq) are spectator ions that's why these are not written in net ionic equation. The Al(PO₄) can not be splitted into ions because it is present in solid form.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.

4) FeSO₄ (aq) + Ba(OH)₂ (aq)

Chemical equation:

FeSO₄ (aq) + Ba(OH)₂ (aq) → BaSO₄(s) + Fe(OH)₂(aq)

The equation is already balanced.

Ionic equation:

Fe²⁺(aq) + SO₄²⁻ (aq) + Ba²⁺(aq) + 2OH⁻ (aq) → BaSO₄(s) + Fe²⁺(aq) + 2OH⁻(aq)

Net ionic equation:

SO₄²⁻ (aq) + Ba²⁺(aq) → BaSO₄(s)

The Fe²⁺ (aq) and OH⁻ (aq) are spectator ions that's why these are not written in net ionic equation. The BaSO₄ can not be splitted into ions because it is present in solid form.

Spectator ions:

These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.

8 0

2 years ago

If the heat of combustion for a specific compound is −1160.0 kJ/mol and its molar mass is 86.47 g/mol, how many grams of this co

notsponge [240]

Answer:

40.34 g

Explanation:

First, we divide the heat to release by the heat of combustion to obtain the required moles of compound:

541.20 kJ/(1160.00 kJ/mol) = 0.4665 mol

So, we have to burn approximately 0.47 mol of the compound. We convert the moles to mass in grams by using the molar mass:

mass = molar mass x moles = 86.47 g/mol x 0.4665 mol = 40.34 g

Therefore, you must burn 40.34 grams of the compound to release 541.20 kJ of heat.

8 0

2 years ago

PLZ HELP, NO MESSING AROUND, WILL GIVE BRAINLIEST!

Vesnalui [34]

<h2>Hey There!</h2><h2>_____________________________________</h2><h2>Answer:</h2><h2>_____________________________________</h2><h2>Covalent Bond:</h2>

Covalent bond is a type of chemical bond which is due to the sharing an electron from each and every atom that is participating in the bond.

<h2>Ionic Bond:</h2>

Ionic bond is a type of bond which is formed due to the complete donation of an electron from one atom to another.

Ionic bond is formed between metals and non-metals. The group which provide the Metal are IA and IIA i.e. S block elements. The group which mostly provide non-metal is VII A i.e. halogens. The Metals give up their ONLY Valance shell electron which is accepted by the Non-metal. This results in formation of ions, The Metals gets the positive charge thus called cation and The non-metal gets a negative charge thus called anion. These Positive and Negative ion attract each other resulting in the formation of IONIC BOND.

The Ionic bond is formed between The metal and non metal because, the metals have low ionization energy due to which the valence shell is ejected out easily, and The Non-Metals have high electron affinity which means that they attract an electron with greater force because they need one electron to complete their octet. As the non metal has high electron affinity and metal have low electron affinity thus the electronegativity difference between the non metal and metal is more than 2 thus they make ionic bond.

<h2>_____________________________________</h2><h2>Rule of Electronegativity:</h2>

Electronegativity is the tendency of an atom to attract shared pair of electron. If there is electronegativity difference between the two atom more than 2 then it makes IONIC BOND. If the electronegativity difference is less than 2, it makes COVALENT BOND.

<h2>_____________________________________</h2><h2>Question:</h2>

The question says, the KCl has ionic bond but HCl has covalent bond, why?

<h2>Answer:</h2>

Answer is that KCl has electronegativity difference between K and Cl atom more than 2 thus it forms ionic bond. H and Cl has electronegativity difference of less than 2 thus it makes Covalent Bond. K donates its valence electron completely to the Chlorine atom because chlorine has much more electronegativity than potassium(K). H shares an electron with chlorine, it is not completely donated. H has pair of electron for sometime and chlorine has pair of electron for sometime, It is because the Chlorine and Hydrogen has less difference of electronegativity so they attract with almost same electronegativity.

<h2>_____________________________________</h2><h2>Best Regards,</h2><h2>'Borz'</h2>

3 0

2 years ago