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2 years ago

If the temperature of 15 grams of water changes from 21C to 24C, how many joules of heat were involved? Show work

Chemistry

1 answer:

goblinko [34]2 years ago

6 0

Answer:

189 Joules

Explanation:

Applying,

Q = cm(t₂-t₁)............. equation 1

Where Q = Heat, c = specific heat capacity of water, m = mass of water, t₁ = Initial Temperature, t₂ = Final temperature.

From the question,

Given: m = 15 grams = 0.015 kg, t₁ = 21 °C, t₂ = 24 °C

Constant: c = 4200J/kg.°C

Substitute these values into equation 1

Q = 0.015×4200×(24-21)

Q = 0.015×4200×3

Q = 189 Joules

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Can someone explain this to me, please?

zimovet [89]

Answer:

Isotopes have same atomic numbers, no. of protons and no. of electrons. Only their no. of neutrons and atomic mass are changed.

Atomic Mass = 24

Atomic No. = 11

Hence,

No. of protons in Na-24 = 11

No. of neutrons = Atomic Mass - Atomic Number

No. of neutrons = 24 - 11

No. of neutrons = 13

Atomic Number = 11

$\rule[225]{225}{2}$

Hope this helped!

<h3>~AH1807</h3><h3>Peace!</h3>

5 0

2 years ago

In an experiment to determine if the height of a cake is determined by the temperature at which is cooked, measuring the height

Bezzdna [24]

Answer:

<u>Dependent variable</u>

Explanation:

In a controlled <em>experiment </em>there will be one independent variable, one dependent variable, and some controlled or constant parameters.

The target of the expermiment is to tes how the dependent variable changes with the independent variable.

So, the scientist will change (manipulate) the independent variable and measure the dependent vabiales.

Here, the temperature will be manipulated (within a range), so this is the independent variable; the height of the cake is the variable whose behavior wants to be determined, so this is the dependent variable. Controlled variables or constants may include the mixture, the size of the pan, the time of cooking, the oven, among others.

6 0

3 years ago

1. How many moles of hydrogen are needed to completely react with two moles of nitrogen?

Arlecino [84]

N2 + 3H2 --> 2NH3

Answer: 6 moles of hydrogen are needed to react with two moles of nitrogen.

Explanation:

4 0

2 years ago

If 11.5 ml of vinegar sample (d=1g/ml) is titrated with 18.5 ml of standardized Sodium hydroxide

insens350 [35]

Answer:

4.83% of acetic acid in the vinegar

Explanation:

3 0

3 years ago

Se ha añadido un evaporador para una alimentación de 11500 kg/dia de zumo de pomelo de forma que evapore 3000 kg/dia de agua por

mamaluj [8]

Answer:

37 %.

Explanation:

¡Hola!

En este caso, para el problema descrito, conocemos la corriente de entrada y la de salida del agua, por lo que podemos obtener el flujo de la corriente que contiene el zumo a la salida una vez el agua fue evaporada:

$F_{sol}=11500kg/dia-3000kg/dia=8500 kg/dia$

Luego, por medio de un balance de zumo de limón en el evaporador en el cual la cantidad que entra es igual a la que sale con sus respectivas concentraciones:

$x_z^{entra}*11500kg/dia=x_z^{sale}*8500kg/dia$

Como la concentración del zumo a la salida es del 50 % (0.50), la de entrada es:

$x_z^{entra}=\frac{x_z^{sale}*8500kg/dia}{11500kg/dia} =\frac{0.50*8500kg/dia}{11500 kg/dia}\\ \\x_z^{entra}=0.37$

Que es igual al 37%.

¡Saludos!

6 0

3 years ago