Answer:
<u>8.08 × </u>
<u> atoms of hydrogen</u>
Explanation:
From the given data, we have two categories of variables (unknowns):
- Amount (moles or mass) of Caffeine
- Amount (moles or mass) of Hydrogen
The longer route would be to solve for these variables first, by determining the number of moles of the Caffeine sample (0.134 moles of C8H10N4O2) from the mass of carbon (12.89 g = 1.07 moles in 6.47 atoms) provided. And then solve for the number of atoms of H. <u><em>[N.B: 1 mole of ANY substance = 6.022 × </em></u><u><em> atoms ]</em></u>
Alternatively and quicker, we can use the mole ratios of the Carbon:Hydrogen atoms in the compound.
8 : 10 ≡ 4 : 5
If 4 moles -- 6.47 atoms
Then 5 moles -- ?? atoms
⇒ No. of atoms of Hydrogen = 
<u>=8.08 × </u><u> atoms of hydrogen</u>
Water can't cool at a single temperature. It must start at a higher temperature, and drop to a lower temperature in order to cool. Unless we know the other temperature, there is no way to calculate the amount of thermal energy released.
The wall would absorb extra heat during the day when the sun is out, then release the heat back into the room when the sun goes down.
Here we have to calculate the heat required to raise the temperature of water from 85.0 ⁰F to 50.4 ⁰F.
10.857 kJ heat will be needed to raise the temperature from 50.4 ⁰F to 85.0 ⁰F
The amount of heat required to raise the temperature can be obtained from the equation H = m×s×(t₂-t₁).
Where H = Heat, s =specific gravity = 4.184 J/g.⁰C, m = mass = 135.0 g, t₁ (initial temperature) = 50.4 ⁰F or 10.222 ⁰C and t₂ (final temperature) = 85.0⁰F or 29.444 ⁰C.
On plugging the values we get:
H = 135.0 g × 4.184 J/g.⁰C×(29.444 - 10.222) ⁰C
Or, H = 10857.354 J or 10.857 kJ.
Thus 10857.354 J or 10.857 kJ heat will be needed to raise the temperature.
Answer: Servsafe 9
Explanation:
Remove food from the surface
clean the surface
rinse the surface
sanitize the surface
allow the surface to air dry
