Answer:
B. is the answer
Explanation:
Energy in form of heat is transferred from the warmer mashed potatoes to the cooler spoon.
<span>Number of moles of Fe(CO)5 = mass/molar mass = (6.0 g) / (195.8955 g/mol) = 0.03 mol
Number of moles of PF3 = (4.0 g)/ (87.97 g/mol) = 0.0455 mol
Number of moles of H2 = (4.0 g) / (2.016 g/mol) = 1.984 mol
From the balanced equation
1 mol of Fe(CO)5 reacts with 2 mol of PF3 and 1 mol of H2
then 0.03 mol of Fe(CO)5 will need 0.03 (2/1) = 0.06 mol of PF3 and 0.03 mol of H2
Since we have less PF3 ( 0.0455 mol instead of 0.06 mol), that is the limiting agent</span>
HC= Hydrocarbon
CH=benzene
Explanation:
HC is Hydrocarbon, how? -- Hydrocarbon, a category of substances consisting only of hydrogen and carbon.
CH is benzene, how? -- benzene is represented by the empirical formula CH, which indicates that a typical sample of the compound contains one atom of carbon (C) to one atom of hydrogen (H).
----(<em>Is</em><em> </em><em>this</em><em> </em><em>what</em><em> </em><em>you</em><em> </em><em>meant</em><em>?</em><em>?</em><em>?</em><em>)</em>
Answer: The empirical formula is 
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of Ca= 55.6 g
Mass of S = 44.4 g
Step 1 : convert given masses into moles.
Moles of Ca =
Moles of S =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Ca = 
For S =
The ratio of Ca : S = 1:1
Hence the empirical formula is
Scientists use carbon-14 to date ancient fossils.
Plants and animals absorb carbon-14 produced by cosmic rays. The ratio of C-14 to C-12 is constant when they are alive.
When they die, the C-14 decays to C-12, and the ratio changes.
Carbon-14 has a half-life of 5730 years. Thus, the object loses half its C-14 every 5730 years.
Scientists can use the C-14 to C-12 ratio to date fossils up to 70 000 years old.
