When a 4 g peanut is burned, it warms 300 ml of water 45 °c. what was the energy content of the peanut?

1 answer:

7 0

Answer is: 13500 cal.
m(water) = V(water)·d(water) = 300ml·1g/ml = 300g.
ΔT = 45°C, temperature change.
Calorie is amount of energy (heat) needed to increase the temperature of one gram of water by 1°C.
To raise the temperature of 300 grams of water for 45°C:
Heat in calories = mass in gram x temperature change °C x specific heat (cal / gram·°C). Q = m·ΔT·c.
Q = 300g · 45°C · 1cal/g·°C = 13500 cal.

You might be interested in

25 g of NH, is mixed with 4 moles of O, in the given reaction:

FromTheMoon [43]

Answer:

a. NH3 is limiting reactant.

b. 44g of NO

c. 40g of H2O

Explanation:

Based on the reaction:

4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l)

4 moles of ammonia reacts with 5 moles of oxygen to produces 4 moles of NO and 6 moles of water.

To find limiting reactant we need to find the moles of each reactant and using the balanced equation find which reactant will be ended first. Then, with limiting reactant we can find the moles of each reactant and its mass:

a. Moles NH3 -Molar mass. 17.031g/mol-

25g NH3*(1mol/17.031g) = 1.47moles NH3

Moles O2 = 4 moles

For a complete reaction of 4 moles of O2 are required:

4mol O2 * (4mol NH3 / 5mol O2) = 3.2 moles of NH3.

As there are just 1.47 moles, NH3 is limiting reactant

b. Moles NO:

1.47moles NH3 * (4mol NO/4mol NH3) = 1.47mol NO

Mass NO -Molar mass: 30.01g/mol-

1.47mol NO * (30.01g/mol) = 44g of NO

c. Moles H2O:

1.47moles NH3 * (6mol H2O/4mol NH3) = 2.205mol H2O

Mass H2O -Molar mass: 18.01g/mol-

2.205mol H2O * (18.01g/mol) = 40g of H2O

3 0

3 years ago

Read 2 more answers

Before entering the cyclotron, the particles are accelerated by a potential difference V. Find the speed v with which the partic

vesna_86 [32]

Answer:

Speed, $v=\sqrt{\dfrac{2qV}{m}}$

Explanation:

The device which is used to accelerate charged particles to higher energies is called a cyclotron. It is based on the principle that the particle when placed in a magnetic field will possess a magnetic force. Just because of this Lorentz force it moves in a circular path.

Let m, q and V are the mass, charge and potential difference at which the particle is accelerated.

The work done by the particles is equal to the kinetic energy stored in it such that,

$qV=\dfrac{1}{2}mv^2$