The rule that applies in this evaluation is that in addition or subtraction operations, the answer (total/difference) should not be more accurate than the least accurate term. In this case, the number with least sig fig is 2.70 or 4.21. The answer here is 9.66 x10-3.
Answer:Rule 1: The oxidation number of an element in its free (uncombined) state is zero — for example, Al(s) or Zn(s). This is also true for elements found in nature as diatomic (two-atom) elements
Explanation:
Answer:
Explanation:
To convert from moles to grams, we must use the molar mass.
Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.
- Hydrogen (H): 1.008 g/mol
- Oxygen (O): 15.999 g/mol
Now, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.
- H₂O= 2(1.008 g/mol) + 15.999 g/mol = 18.015 g/mol
Use the molar mass as a ratio.
Multiply by the given number of moles.
The moles of water will cancel.
Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.
There are about <u>54 grams</u> of water in 3 moles.
There are 1,000 milligrams (mg) in one gram:
In 10 grams, there are 10 x 1,000 = 10,000 milligrams. This is a lethal dose of caffeine.
There are 4.05 mg/oz (milligrams/ounce) of caffeine in the soda.
In a 12 ounce can, there are 4.05 x 12 = 48.6 milligrams.
How many sodas would it take to kill you?
To find this, we divide the lethal dose amount (10,000 mg) by the amount of caffeine per can (48.6 mg).
10,000 ÷ 48.6 = 205.76.
Since 205 cans is not quite 10,000 mg, technically it would take 206 cans of soda to consume a lethal dose of caffeine.
