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arsen [322]
2 years ago
9

20 points to whoever can answer these 3 questions correctly

Chemistry
1 answer:
vazorg [7]2 years ago
5 0

Answer:

1.true

2.2

3. false

Explanation:

.........

You might be interested in
Given that Δ H ∘ f [ Br ( g ) ] = 111.9 kJ ⋅ mol − 1 Δ H ∘ f [ C ( g ) ] = 716.7 kJ ⋅ mol − 1 Δ H ∘ f [ CBr 4 ( g ) ] = 29.4 kJ
JulsSmile [24]

Answer:

283.725 kJ ⋅ mol − 1

Explanation:

C(s) + 2Br2(g) ⇒ CBr4(g) , Δ H ∘ = 29.4 kJ ⋅ mol − 1

\frac{1}{2}Br2(g) ⇒ Br(g) ,  Δ H ∘ = 111.9 kJ ⋅ mol − 1

C(s) ⇒ C(g) ,  Δ H ∘ = 716.7 kJ ⋅ mol − 1

4*eqn(2) + eqn(3) ⇒ 2Br2(g) + C(s) ⇒ 4 Br(g) + C(g) , Δ H ∘ = 1164.3 kJ ⋅ mol − 1

eqn(1) - eqn(4) ⇒ 4 Br(g) + C(g) ⇒ CBr4(g) , Δ H ∘ = -1134.9 kJ ⋅ mol − 1

so,

   average bond enthalpy is \frac{1134.9}{4} = 283.725 kJ ⋅ mol − 1

4 0
3 years ago
You find apiece of limestone on ahike. what substances are likely to have formed that rock?
enyata [817]

Limestone is mainly made up of calcium carbonate, CaCO3. When it is heated, it breaks down to form calcium oxide and carbon dioxide. Calcium oxide reacts with water to produce calcium hydroxide. But if u wanna know how it is formed? It's formed by erosion and weathering which is a type of 'Sedimentary Rock'. Erosion and weathering, carried rocks and end up at the sea or ocean. Which is the end way to go! At there, rocks combined by adding more and more just under the sea. The combination of rocks made it harden. First, it was just small little eroded particles end up at the sea. But at last, it became a very hard rock which isn't easy to break!

7 0
3 years ago
Copper oxide, CuO, reacts with hydrochloric acid, HCI, to produce copper chloride, CuCL2 and water
spayn [35]

Explanation:

El óxido de cobre (II), también llamado antiguamente óxido cúprico ({\displaystyle {\ce {CuO}}}{\displaystyle {\ce {CuO}}}), es el óxido de cobre con mayor número de oxidación. Como mineral se conoce como tenorita.

{\displaystyle {\ce {2Cu + O2 = 2CuO}}}{\displaystyle {\ce {2Cu + O2 = 2CuO}}}

Aquí, se forma junto con algo de óxido de cobre (I) como un producto lateral, por lo que es mejor prepararlo por calentamiento de nitrato de cobre (II), hidróxido de cobre (II) o carbonato de cobre (II):

{\displaystyle {\ce {2 Cu(NO3)2 = 2 CuO + 4 NO2+ O2}}}{\displaystyle {\ce {2 Cu(NO3)2 = 2 CuO + 4 NO2+ O2}}}

{\displaystyle {\ce {Cu(OH)2 (s) = CuO (s) + H2O (l)}}}{\displaystyle {\ce {Cu(OH)2 (s) = CuO (s) + H2O (l)}}}

{\displaystyle {\ce {CuCO3 = CuO + CO2}}}{\displaystyle {\ce {CuCO3 = CuO + CO2}}}

El óxido de cobre (II) es un óxido básico, así se disuelve en ácidos minerales tales como el ácido clorhídrico, el ácido sulfúrico o el ácido nítrico para dar las correspondientes sales de cobre (II):

{\displaystyle {\ce {CuO + 2 HNO3 = Cu(NO3)2 + H2O}}}{\displaystyle {\ce {CuO + 2 HNO3 = Cu(NO3)2 + H2O}}}

{\displaystyle {\ce {CuO + 2 HCl =CuCl2 + H2O}}}{\displaystyle {\ce {CuO + 2 HCl =CuCl2 + H2O}}}

{\displaystyle {\ce {CuO + H2SO4 = CuSO4 + H2O}}}{\displaystyle {\ce {CuO + H2SO4 = CuSO4 + H2O}}}

Reacciona con álcali concentrado para formar las correspondientes sales cuprato.

{\displaystyle {\ce {3 XOH + CuO + H2O = X3[Cu(OH)6]}}}{\displaystyle {\ce {3 XOH + CuO + H2O = X3[Cu(OH)6]}}}

Puede reducirse a cobre metálico usando hidrógeno o monóxido de carbono:

{\displaystyle {\ce {CuO + H2 = Cu + H2O}}}{\displaystyle {\ce {CuO + H2 = Cu + H2O}}}

{\displaystyle {\ce {CuO + CO = Cu + CO2}}}{\displaystyle {\ce {CuO + CO = Cu + CO2}}}

6 0
3 years ago
Does anyone know how to do this? the solubility of barium carbonate, BaCO3, is 0.0100 g/L. Its molar mass is 197.3 g/mol. What i
g100num [7]
It's simple, just follow my steps.

1º - in 1 L we have 0.0100~g of BaCO_3

2º - let's find the number of moles.

\eta=\frac{m}{MM}

\eta=\frac{0.0100}{197.3}

\boxed{\boxed{\eta=5.07\times10^{-5}~mol}}

3º - The concentration will be

C=5.07\times10^{-5}~mol/L

But we have this reaction

BaCO_3\rightleftharpoons Ba^{2+}+CO_3^{2-}

This concentration will be the concentration of Ba^{2+}~~and~~CO_3^{2-}

K_{sp}=\frac{[Ba^{2+}][CO_3^{2-}]}{[BaCO_3]}

considering [BaCO_3]=1~mol/L

K_{sp}=[Ba^{2+}][CO_3^{2-}]

and

[Ba^{2+}]=[CO_3^{2-}]=5.07\times10^{-5}~mol/L

We can replace it

K_{sp}=(5.07\times10^{-5})*(5.07\times10^{-5})

K_{sp}\approx25.70\times10^{-10}

Therefore the K_{sp} is:

\boxed{\boxed{\boxed{K_{sp}\approx2.57\times10^{-11}}}}
4 0
3 years ago
Read 2 more answers
Transuranium elements are artificial and may be prepared by a fusion process in which heavy nuclei are bombarded with light ones
Scilla [17]

Answer:

_{97}^{345}\textrm{Bk}

Explanation:

In a nuclear reaction, the total mass and total atomic number remains the same.

Am has an atomic number of 95. So correct reaction is:-

^{343}_{95}\textrm{Am}+^{4}_{2}\textrm{He}\rightarrow ^A_Z\textrm{X}+2^1_0\textrm{n}

To calculate A:

Total mass on reactant side = total mass on product side

343 + 4 = A + 2

A = 345

To calculate Z:

Total atomic number on reactant side = total atomic number on product side

95 + 2 = Z + 0

Z = 97

Hence, the isotopic symbol of unknown element is _{97}^{345}\textrm{Bk}

7 0
3 years ago
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