Which statement is true about a fuel cell

When 1.98g of a hydrocarbon is burned in a bomb calorimeter, the temperature increases by 2.06∘C. If the heat capacity of the ca

schepotkina [342]

Answer:

8.3 kJ

Explanation:

In this problem we have to consider that both water and the calorimeter absorb the heat of combustion, so we will calculate them:

q for water:

q H₂O = m x c x ΔT where m: mass of water = 944 mL x 1 g/mL = 944 g

c: specific heat of water = 4.186 J/gºC

ΔT : change in temperature = 2.06 ºC

so solving for q :

q H₂O = 944 g x 4.186 J/gºC x 2.06 ºC = 8,140 J

For calorimeter

q calorimeter = C x ΔT where C: heat capacity of calorimeter = 69.6 ºC

ΔT : change in temperature = 2.06 ºC

q calorimeter = 69.60J x 2.06 ºC = 143.4 J

Total heat released = 8,140 J + 143.4 J = 8,2836 J

Converting into kilojoules by dividing by 1000 we will have answered the question:

8,2836 J x 1 kJ/J = 8.3 kJ

7 0

3 years ago

What is made from a chemical reaction?

denis23 [38]

Answer:

the Product

Explanation:

4 0

3 years ago

How does the mass of an electron compare to the mass of a proton and a

tensa zangetsu [6.8K]

Answer:

C. The mass of an electron is much less than the mass of a proton or

a neutron.

Explanation:

When we compare the mass of an electron to that of proton or neutron, the mass of an electron is much less than the mass of a proton or a neutron.

Electrons are negatively charged particles in an atom

Protons are positively charged particles

Neutrons do not carry any charges.

The relative mass of an electron compared to that of a proton is $\frac{1}{1840}$
This is a very small value
Electrons generally have mass of 9.11 x 10⁻³¹kg
Protons weigh 1.67 x 10⁻²⁷kg

Neutrons weigh 1.68 x 10⁻²⁷kg

We can see that electrons have very small mass and this is why when calculating the mass of an atom, we use the sum of the number of protons and neutrons.

6 0

3 years ago

what is the half life isotope if after 21 days you have 31.25 g remaining from a 250.0 g starting sample size?

alexgriva [62]

250 --> 125 --> 62.5 --> 31.25

each arrow equals one half life, so 3 half lives

14 days/ 3 half lives =

4.67 days = half life

3 0

3 years ago

Which one of the following statements is not true concerning 2.00 L of a 0.100 M solution of Ca3(PO4)2?

Len [333]