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mylen [45]
3 years ago
10

The energy from 0.015 moles of octane was used to heat 250 grams of water. The temperature of the water rose from 293.0 K to 371

.2 K. What is the enthalpy of combustion of octane? The specific heat capacity of water is 4.18 J/K g.
Chemistry
1 answer:
Bas_tet [7]3 years ago
8 0

Answer:

5447.93 KJ

Explanation:

Given:

The number of moles of octane , n = 0.015

Mass of the water heated, m = 250 grams

Temperature change of the water, ΔT = 371.2 K - 293.0 K = 78.2 K

The specific heat capacity of the water, C = 4.18 J/k g

Now,

the heat acquired by the water, Q

Q = mCΔT

on substituting the values, we get

Q = 250 × 4.18 × 78.2

or

Q = 81.719 KJ

Now, the heat of combustion = Q / n = 81.719 / 0.015  = 5447.93 KJ

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Misha Larkins [42]

Answer:

C. An atom consists of positively charged matter that contains negatively charged particles.

Explanation:

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3 years ago
Suppose Earth was tilted much less on its axis. What effect would this have on the planet? Please help me !
hodyreva [135]

Answer:

If Earth was tilted much less on its axis, it would lead to minor changes in precipitation and temperatures as Earth moves slightly towards and away from the sun.

Explanation:

If a planet tilts more, it leads to colder winters and warmer summers. However, if a planet tilts less, it leads to less severe seasons that is and milder winters and cooler summers.

If Earth was tilted much less on its axis, it would lead to minor changes in precipitation and temperatures as Earth moves slightly towards and away from the sun.

6 0
2 years ago
If 30.0 mL of 0.150 M CaCl₂ is added to 38.5 mL of 0.100 M AgNO3, what is the mass of the AgCl precipitate?
Ksenya-84 [330]

If 30.0 mL of 0.150 M CaCl₂ is added to 38.5 mL of 0.100 M AgNO3. The mass of the AgCl precipitate is 0.552 g.

<h3>What is Stoichiometry ?</h3>

Stoichiometry helps us use the balanced chemical equation to measure quantitative relationships and it is to calculate the amounts of products and reactants that are given in a reaction.

<h3>What is Balanced Chemical Equation ?</h3>

The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.

Now we have to write the balanced equation

2AgNO₃ + CaCl₂ →  2AgCl + Ca(NO₃)₂

Molecular Weight of CaCl₂ = 110.98 g/mol

Molecular Weight of AgNO₃ = 170.01 g/mol

Molecular Weight of AgCl = 143.45 g/mol

Here,

Volume of CaCl₂ = 30.0 mL = 0.03L

Volume of AgNO₃ = 38.5 mL = 0.0385 L

Now find the number of moles

Number of moles = Volume × Molarity

                         

Number of moles of CaCl₂ = 0.03 L × 0.150

                                             = 0.00456 mol

Number of moles of AgNO₃ = 0.0385 L × 0.100

                                               = 0.00385 mol

The stoichiometric ratio of AgNO₃ to CaCl₂ is 2:1.

= \frac{0.00385}{2}

= 0.001925 mol                      

According to Stoichiometry Mass of AgCl

= 0.0385  \times \frac{0.1}{1\ \text{mol}} \times \frac{2\ \text{mol} AgCl}{2\ \text{mol} AgNO_3} \times \frac{143.4\ g}{1\ \text{mol}}

= 0.552 g AgCl

Thus from the above conclusion we can say that If 30.0 mL of 0.150 M CaCl₂ is added to 38.5 mL of 0.100 M AgNO3. The mass of the AgCl precipitate is 0.552 g.

Learn more about the Stoichiometry here: brainly.com/question/16060223

#SPJ1

5 0
1 year ago
2Al + 3H2SO4 -&gt; Al2(SO4)3 + 3H2How many grams of aluminum sulfate would be formed if 250g H2SO4 completely reacted with alumi
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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

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