im not sure about the answer sorry in advance if it's wrong
Answer:
Number of half lives = 5
Explanation:
Given data:
Half life of oxygen = 2 min
Half lives occured in 10 min = ?
Solution:
Formula;
Number of half lives = Time elapsed / half life
by putting values,
Number of half lives = 10 min / 2 min
Number of half lives = 5
Answer:
The correct answer is 117.68 g
Explanation:
In order to calculate the mass the chemist has to weigh, we have to multiply the concentration of the solution (0.200 M) by the volume (2.00 L). As the concentration is given in M (mol/L) we first have to convert the concentration from molarity to g/L by using the molecular weight of K₂Cr₂O₇.
From the Periodic Table we know the molar mass (MM) of the constituting elements K, Cr and O:
molecular weight K₂Cr₂O₇= (2 x MM K) + ( 2 x MM Cr) + (7 x MM O)
molecular weight K₂Cr₂O₇= (2 x 39.1 g/mol) + ( 2 x 52 g/mol) + ( 7+ 16 g/mol)
molecular weight K₂Cr₂O₇= 294.2 g/mol
Finally, we can calculate the mass as follows:
mass= 0.200 mol/L x 294.2 g/mol x 2.00 L= 117.68 g
I believe it’s 2 moles or iron
Answer:
The air that we breathe in enters the nose or mouth, flows through the throat (pharynx) and voice box (larynx) and enters the windpipe (trachea). The trachea divides into two hollow tubes called bronchi
Explanation: