All categories

3 years ago

A chemical reaction gives off 1,500 kj of heat energy. about how many calories is this? (1 calorie = 4.18 joules)

Chemistry

2 answers:

Greeley [361]3 years ago

6 0

1500kj = 15x 10^5 j
1 calorie = 4.18 j
(15 x 10^5)/4.18= 3.58 x 10^5

Answer is a

Zanzabum3 years ago

3 0

Answer is: a. 3.6 x 10^5 calories.

E = 1500 kJ; heat energy.

E = 1500 kJ · 1000 J/kJ.

E = 1500000 J = 1.5·10⁶ J.

E = 1.5·10⁶ J ÷ 4.18 J/cal.

E = 3.6·10⁵ cal.

Calorie (cal), or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.

One small calorie is approximately 4.18 joules.

A calorie is a unit of energy.

You might be interested in

If 5.58 g of iron reacts with sulfur to produce 8.79 g of iron sulfide, what is the mass of reacting sulfur? A) 3215 B) 14:37 C)

gogolik [260]

Answer: A) 3.21 g

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.

$Fe+S\rightarrow FeS$

We are given:

Mass of iron = 5.58 g

Mass of iron sulphide = 8.79 g

Mass of sulphur = x g

Total mass on reactant side = 5.58 + x

Total mass on product side = 8.79 g

Applying law of conservation of mass, we get:

$5.58+x=8.79\\\\x=3.21g$

Hence, the mass of reacting sulfur is 3.21 g.

7 0

3 years ago

The net ionic equation for formation of an aqueous solution of nii2 accompanied by evolution of co2 gas via mixing solid nico3 a

Ann [662]

Answer:

NiCO3 (s) + 2H+ (aq) → H2O (l) + CO2 (g) + Ni2+ (aq)

Explanation:

To write the complete ionic equation:

1. Start with a balanced molecular equation.

2. Break all soluble strong electrolytes (compounds with (aq) beside them) into their ions

3. indicate the correct formula and charge of each ion

4. indicate the correct number of each ion

5. write (aq) after each ion

6. Bring down all compounds with (s), (l), or (g) unchanged.

8 0

3 years ago

A group of students conducted an experiment to determine the effect of heat on the germination(sprouting) of sunflower seeds. Wh

pentagon [3]

what grade is this because apparently i like to know what grade it is before i solve it

3 0

3 years ago

Near the ceiling of a room air is warmer. The warm air rises because of

Amiraneli [1.4K]

Answer:

convection

Explanation:

heat will always rise

3 0

4 years ago

Read 2 more answers

Calculate the ph of sweater which has a hydrogen ion concentration of 1 times 10 to the power of 8

telo118 [61]

Answer:

The pH of the sweater containing Hydrogen ion concentration

$[H^{+}]=1\times 10^{-8}$ is

8

Explanation:

pH = It is the negative logarithm of activity (concentration) of hydrogen ions.

pH = -log([H+])

Now, In the question the concentration of [H+] ions is :

$[H^{+}]=1\times 10^{-8}$

$pH = -log(1\times 10^{-8})$

use the relation:

$log(10^{-a})=a$

$pH= -(-8)$

pH = 8

Note : 1 times 10 to the power of 8 must be" 1 times 10 to the power of -8"

If the concentration is

$[H^{+}]=1\times 10^{8}$

Then pH = -8 , which is not possible . So in that case the pH calculation is by other method

5 0

3 years ago