Answer:
∴ Q = -7.52kCal
Explanation:
Using the formula for specific heat capacity:
Q = mcΔT
where ΔT = change in temperature (final - initial) = (0 - 100)°C = -100°C
m = mass (g) = 75g
c = specific heat capacity = 4.2 J/g°C in water
⇒ Q = 75 × 4.2 × -100
= -31,500J
But 1J - 0.000239kCal
<u>∴ Q = -7.52kCal</u>
<u />
Let me know if I can be of further assistance.
Answer:
Explanation:
specific heat of granite s = .79 J / g / k
let the mass of granite = m
heat lost by granite = heat gained by water
heat lost = mass x specific heat x drop in temperature
= m x .79 x (80 - 20.45)
heat gained by water
= 3000 x 4.186 x (20.45- 20)
heat lost by granite = heat gained by water
m x .79 x 59.55 = 3000 x 4.186 x .45
m = 120.12 g .
Answer:
1. light is made up of energy
2. light travels in a straight line
3. the speed of light is exactly 299 792 km per second
4. this is the speed when light is traveling in a vacuum and not obstructed by the atmosphere 5. traveling at the speed of light you could go around the earth seven and a half times in a second
6. light can move super fast super slow and not at all
7. we can use light to weigh Stars
8. we can use light as tweezers
9. bubbles can turn sound into light
10. lasers can make things cold
Answer:
(A) 0.129 M
(B) 0.237 M
Explanation:
(A) The reaction between potassium hydrogen phthalate and barium hydroxide is:
- 2HA + Ba(OH)₂ → BaA₂ + 2H₂O
Where A⁻ is the respective anion of the monoprotic acid (KC₈H₄O₄⁻).
We <u>convert mass of phthalate to moles</u>, using its molar mass:
- 0.978 g ÷ 156 g/mol = 9.27x10⁻³ mol = 9.27 mmol
Now we <u>convert mmol of HA to mmol of Ba(OH)₂</u>:
- 9.27 mmol HA *
= 6.64 mmol Ba(OH)₂
Finally we calculate the molarity of the Ba(OH)₂ solution:
- 6.64 mmol / 35.8 mL = 0.129 M
(B) The reaction between Ba(OH)₂ and HCl is:
- 2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O
So<u> the moles of HCl that reacted </u>are:
- 17.1 mL * 0.129 M *
= 4.41 mmol HCl
And the <u>molarity of the HCl solution is</u>:
- 4.41 mmol / 18.6 mL = 0.237 M
