Answer:
I needed to use good precision in my measurement for my chemistry lab
Explanation:
First. moles is just a label for a number of things. just like a
dozen = 12, a gross = 144, a mole = 6022 with another 20 zeros after the
2
next
moles = mass / molecular weight.
molecular weight = sum of atomic mass from the periodic table
atomic mass MnO2 = atomic mass Mn + 2 x atomic mass O
= 54.94 + 2 x 16 = 86.94 g/mole
so moles MnO2 = 98.0 grams / (86.94 g/mole) = 1.13 moles
notice that I only gave 3 digits? that because of sig figs read the link below if you don't understand....
mw C5H12 = 5 x 12 + 12 x 1 = 72 g/mole
so moles C5H12 = 12.0 g / 72.0 g/mole = 0.167 moles
mw XeF6 = 131.3+ 6 x 19.00 = 245.3
so moles XeF6 = 100 g / 245.3 g/mole = 0.4077 moles
I've also provided a link to a periodic table. if you need atomic weights click on any element and it will give you the
details.
we need to get the total calories, we can get it by getting the average of calories of the protein, fat, and carbohydrates:
calories of protein = 15g x 4 KCal/g
= 60 KCal
calories of fat = 1 g x 9 KCal/g
= 9 kCal
calories of carbohydrates = 42 g x 4 KCal/g
= 168 Kcal
∴ the total calories = 60 + 9 + 168 = 237Kcal = 0.237 Cal
to get the resualt to two significant figures
∴ the resault is = 0.24 Cal = 240 KCal
A
It is referred to as the Great Oxygenation Event. During this time, photosynthetic organisms evolved and begun utilizing sunlight for energy. They captured this energy into chemical energy. These organisms took up carbon dioxide and evolved oxygen into the atmosphere.
Explanation:
Oxygen levels in the atmosphere rose drastically as those of carbon dioxide and methane dropped. This increase of oxygen in the atmosphere also allowed the formation of an ozone layer that protects genetic material from UV light. This largely enabled organisms to conquer land.
Learn More:
For more on the Great Oxygenation Event check out;
brainly.com/question/11255683
#LearnWithBrainly
Answer:
It would be an element my dear.
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Pure gold is an element. That is, it is not a combination of other materials. However, gold used in jewelry is usually a “mixture”, called an alloy mixed with other metals to harden it, to change the color as in copper makes the pink or rose gold that is currently enjoying great polarity.
