All of these are compounds except oxygen because a compound is two or more different elements bonded together.
I’m assuming you mean barium nitrite, Ba(NO2)2.
First convert grams of Ba(NO2)2 to moles using the molar mass of Ba(NO2)2. Then use the mole ratio of 4 moles of oxygen per 1 mole of Ba(NO2)2 to convert to moles of oxygen. Then use the molar mass of oxygen to convert to grams of oxygen.
45.7 g Ba(NO2)2 • 1 mol Ba(NO2)2 / 229.35 g Ba(NO2)2 • 4 mol O / 1 mol Ba(NO2)2 • 16.0 g O / 1 mol O = 12.8 g oxygen
Answer:
photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
I believe you mean what amount of O2 contains 1.8 x 10^22 molecules.
Solution: Divide your number of molecules by the number of molecules in one mole (6.02 x l0^23)
02989 moles. Rounded to the nearest hundredths,.<span>0299</span>
<u>Answer:</u> The mass of sucrose required is 69.08 g
<u>Explanation:</u>
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:

Or,

where,
= osmotic pressure of the solution = 8.80 atm
i = Van't hoff factor = 1 (for non-electrolytes)
Mass of solute (sucrose) = ?
Molar mass of sucrose = 342.3 g/mol
Volume of solution = 564 mL (Density of water = 1 g/mL)
R = Gas constant = 
T = Temperature of the solution = 290 K
Putting values in above equation, we get:

Hence, the mass of sucrose required is 69.08 g