All categories

2 years ago

Which of the following is an example of chemical energy being released or stored?

Chemistry

1 answer:

Monica [59]2 years ago

7 0

Answer:

Explanation:

When something is chemical it is warped into a completely new substance and when coal is burned it is new so it is definitely C.

You might be interested in

D‑Glucose and L‑glucose are

tensa zangetsu [6.8K]

Answer:

<h3>A. Epimers </h3>

Explanation:

3 0

3 years ago

Read 2 more answers

At 2°C, the vapor pressure of pure water is 23.76 mmHg and that of a certain seawater sample is 23.09 mmHg. Assuming that seawat

wariber [46]

Answer:

0.808 M

Explanation:

Using Raoult's Law

$\frac{P_s}{Pi}= x_i$

where:

$P_s$ = vapor pressure of sea water( solution) = 23.09 mmHg

$P_i$ = vapor pressure of pure water (solute) = 23.76 mmHg

$x_i$ = mole fraction of water

∴

$\frac{23.09}{23.76}= x_i$

$x_i = 0.9718$

$x_i+x_2=1$

$x_2 = 1- x_i$

$x_2 = 1- 0.9718$

$x_2 = 0.0282$

$x_i = \frac{n_i}{n_i+n_2}$ ------ equation (1)

$x_2 = \frac{n_2}{n_i+n_2}$ ------ equation (2)

where; $(n_2) =$ number of moles of sea water

$(n_i) =$ number of moles of pure water

equating above equation 1 and 2; we have :

$\frac{n_2}{n_i}$ $= \frac{0.0282}{0.9178}$

$= 0.02901$

NOW, Molarity = $\frac{moles of sea water}{mass of pure water }*1000$

$= \frac{0.02901}{18}*1000$

$= 0.001616*1000$

$= 1.616 M$

As we assume that the sea water contains only NaCl, if NaCl dissociates to Na⁺ and Cl⁻; we have $\frac{1.616}{2} =0.808 M$

3 0

2 years ago

Read 2 more answers

Use the following periodic table to help you. Which of the following would be classified as a metalloid?

Rama09 [41]

Silicon is a metalloid

4 0

3 years ago

Conditions for an experimental chemistry reaction require a temperature of 300 K. The temperature in the lab is 55 F. Which of t

OLga [1]

The suggested answers are for K=298 degrees and the nearest correct answer seems to be increase the room temperature by 22 degrees Fahrenheit. But by calculation, for 300 K, then convert 300k to degrees Celsius = 300-273.15=26.85 degrees celsius. Then convert the 26.85 to degrees F, so F=9/5C + 32= 48.33+32=80.33-55F (present room temperature)=25.33 degrees F to increase the room temperature by.

6 0

2 years ago

Read 2 more answers

An atom has 6 protons and 9 neutrons in its nucleus. Calculate the mass number of the atom

pshichka [43]

Answer:

6+9=15

mass number =15

mass number = no. protons + no. of neutrons

5 0

2 years ago