Answer:
I think no C or D
if wrong correct me plsssssss
Mark me brainliest plsss
Explanation:
December 21 marks the winter solstice in the Northern Hemisphere, but in 2020 the longest night of the year is also going to be a witness to an incredible astronomic event known as the “great conjunction”. ... This rare double planet sighting–or “Great Conjunction”–can be viewed from anywhere around the globe
Answers:
See below
Step-by-step explanation:
1. Most food energy
(a) Pringles
Heat from Pringles + heat absorbed by water = 0
m₁ΔH + m₂CΔT = 0
1.984ΔH + 100 × 4.184 × 18 = 0
1.984ΔH + 7530 = 0
ΔH = -7530/1.984 = -3800 J/g
(b) Cheetos
0.884ΔH + 418.4 × 13 = 0
ΔH = -5400/0.884 = -6200 J/g
Cheetos give you more food energy per gram.
(c) Snickers
Food energy = 215 Cal/28 g × 4184 J/1 Cal = 32 000 J/g
The food energy from Cheetos is much less than that from a Snickers bar
2. Experimental uncertainty
The experimental values are almost certainly too low.
Your burning food is heating up the air around it, so much of the heat of combustion is lost to the atmosphere.
3. Percent efficiency
Experimental food energy = 3800 J/g
Actual food energy = 150 Cal/28 g × 4184 J/1 Cal = 22 000 J/g
% Efficiency = Experimental value/Actual value × 100 %
= 3800/22 000 × 100 %
= 17 %
Answer:
Percent yield = 94.62%
Explanation:
Given data:
Actual yield of BeBr₂ = 1.23 mol
Theoretical yield of BeBr₂ = 220 g
Percent yield = ?
Solution:
Theoretical yield in moles:
Number of moles = mass/molar mass
Number of moles = 220 g/168.82 g/mol
Number of moles = 1.30 mol
Percent yield:
Percent tiled = actual yield / theoretical yield × 100
by putting values,
Percent yield = 1.23 mol / 1.30 mol × 100
Percent yield = 0.9462 × 100
Percent yield = 94.62%
Convert to grams to moles, convert g of water to litres, divide moles by litres = M
Yes I think yesi,m not really suer
