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Anni [7]
3 years ago
6

What is the energy change if 84.0 g of calcium oxide (CaO) reacts with excess water in the following reaction?

Chemistry
1 answer:
pochemuha3 years ago
6 0
   The energy change  if 84.0 g   of CaO  react  with  excess  water is  98KJ of heat is released.

calculation
heat  =  number of moles  x  delta H

delta H = - 65.2  Kj/mol

first find the number of  moles  of  CaO reacted

moles = mass/molar mass
the molar mass  of CaO =  40 +  16=  56 g/mol
mass = 84 g
moles therefore = 84 g/56 g/mol =1.5 moles

Heat is therefore =  1.5 moles  x -65.2 = - 97.8 Kj = -98 Kj

  since  sign is  negative  the   energy  is released 

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bazaltina [42]

Answer:

290.82g

Explanation:

The equation for the reaction is given below:

2Al + 3H2SO4 -> Al2(SO4)3 + 3H2 now, let us obtain the masses of H2SO4 and Al2(SO4)3 from the balanced equation. This is illustrated below:

Molar Mass of H2SO4 = (2x1) + 32 + (16x4) = 2 + 32 +64 = 98g/mol

Mass of H2SO4 from the balanced equation = 3 x 98 = 294g

Molar Mass of Al2(SO4)3 = (2x27) + 3[32 + (16x4)]

= 54 + 3[32 + 64]

= 54 + 3[96] = 54 + 288 = 342g

Now, we can obtain the mass of aluminium sulphate formed by doing the following:

From the equation above:

294g of H2SO4 produced 342g of Al2(SO4)3.

Therefore, 250g of H2SO4 will produce = (250 x 342)/294 = 290.82g of Al(SO4)3

Therefore, 290.82g of aluminium sulphate (Al(SO4)3) is formed.

7 0
3 years ago
How many total valence electrons are available for the Lewis Dot structure of H2S?
Anettt [7]

Answer:

8 Valence Electrons

Explanation:

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The correct answer to the following question will be "Arrhenius base".

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  • This acid, as well as base model, claims an acid is indeed a material that incorporates hydrogen or ionizes protons throughout aqueous, while a base would be a material that comprises hydroxide while releases everything in a that solution

So that the above is the right answer.

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