All categories

3 years ago

How much energy, in joules, is released when 17 kilograms of granite is cooled from 45 C to 21 C?

1 answer:

6 0

The final answer is -322, 320 Joules. The solution for the problem is:

The equation that must be used in this problem is:

U = mCp(Tf-Ti)

where:
U = energy released or absorbed in Joules
m = mass in kg
Cp = specific heat of material in J/kg-C
Tf = final temperature, C
Ti = initial temperature, C

Looking up the Cp of granite gives a value of 790 J/kg-C.

U = 17kg (790 J/kg-C) (21-45)
U = - 322, 320 Joules (negative means heat is released)

You might be interested in

4. Methane, CH4, is one carbon atom bonded to four hydrogen atoms. In order to show

oee [108]

The answer is C. the carbon symbol C with one dot on each

the top, bottom, left, and right sides

8 0

3 years ago

The combustion of glucose (c6h12o6) with oxygen gas produces carbon dioxide and water. this process releases 2803 kj per mole of

V125BC [204]

Answer:- 335 kcal of heat energy is produced.

Solution:- The balanced equation for the combustion of glucose in presence of oxygen to give carbon dioxide and water is:

$C_6H_1_2O_6+6O_2\rightarrow 6CO_2+6H_2O$

From given info, 2803 kJ of heat is released bu the combustion of 1 mol of glucose. We need to calculate the energy produced when 3.00 moles of oxygen react with excess of glucose.

We could solve this using dimensional analysis as:

$3.00mol O_2(\frac{1mol glucose}{6mol O_2})(\frac{2803 kJ}{1mol glucose})$

= 1401.5 kJ

Now, let's convert kJ to kcal.

We know that, 1kcal = 4.184kJ

So, $1401.5kJ(\frac{1kcal}{4.184kJ})$

= 335 kcal

Hence, 335 kcal of heat energy is produced by the use of 3.00 moles of oxygen gas.

8 0

3 years ago

Which of these are ionic compounds? Check all that apply.

SIZIF [17.4K]

I think the correct answers from the choices listed above are the first, third and the last option. Ionic compounds are compounds that dissociates into ions when in aqueous solution. From the list, NH4Cl, KF and MgO are the ionic compounds. Hope this answers the question.

5 0

3 years ago

Read 2 more answers

How many atoms are in 1.50 moles of Hg?

Oxana [17]

Answer:

Atoms=9.033*10^23 atoms

Explanation:

Atoms=no.of miles*Avogadro's no.

Atoms=1.5*6.022*10^23

Atoms=9.033*10^23 atoms

3 0

3 years ago

Read 2 more answers

Glucose, C6H12O6,C6H12O6, is used as an energy source by the human body. The overall reaction in the body is described by the eq

Ilia_Sergeevich [38]

Answer:

Mass of oxygen = 61.824 g

Mass of carbon dioxide = 85.01 g

Explanation:

Given data:

Mass of glucose = 58 g

Mass of carbon dioxide = ?

Mass of oxygen = ?

Solution:

First of all we will write the balanced chemical equation,

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Moles of glucose:

Number of moles = mass / molar mass

Number of moles = 58 g/180 g/mol

Number of moles = 0.322 mol

Now we compare the moles of oxygen with glucose from balance chemical equation.

C₆H₁₂O₆ : O₂

1 : 6

0.322 : 0.322×6 = 1.932 mol

Mass of oxygen:

Mass of oxygen = number of moles × molar mass

Mass of oxygen = 1.932 mol × 32 g/mol

Mass of oxygen = 61.824 g

Now we compare the moles of carbon dioxide with moles of glucose and oxygen.

C₆H₁₂O₆ : CO₂

1 : 6

0.322 : 0.322×6 = 1.932 mol

O₂ : CO₂

6 : 6

1.932 : 1.932

Mass of carbon dioxide;

mass of carbon dioxide = number of moles × molar mass

mass of carbon dioxide = 1.932 mol × 44 g/mol

mass of carbon dioxide = 85.01 g

7 0

3 years ago