Answer:
0.125 moles
Explanation:
2.8 litres is equivalent to 2.8dm³
At STP,
1 mole = 22.4 dm³
x mole = 2.8 dm³
Cross multiply
22.4x = 2.8
Divide both sides by 22.4
x = 2.8/22.4
x = 0.125
To calculate the average mass of the element, we take the summation of the product of the isotope and the percent abundance. In this case, the equation becomes 186.207=187*0.626+185*x where x is the percent abundance of 185. The answer is 0.374 or 37.4%. This can also be obtained by 100%-62.6%= 37.4%.
Answer:
mass P4 = 35.998 g
Explanation:
∴ STP: P = 1 atm; T = 298 K
∴ V O2= 35.5 L
⇒ nO2 = P.V / R.T
∴ R = 0.082 atm.L/K.mol
⇒ nO2 = ((1 atm)×(35.5L))/((0.082 atm.L/K.mol)(298K))
⇒ nO2 = 1.453 mol O2
⇒ mol P4 = (1.453 molO2)×(mol P4/ 5molO2) = 0.2906 mol P4
∴ Mw P4 = 123.895 g/mol
⇒ mass P4 = (0.2906 mol P4)×(123.895 g/mol) = 35.998 g P4
Similar chemical properties
(OPTION C)
<span>Most bonds are made when a positive atom or molecule (one that is missing an electron in its outer shell) accepts an electron from a negative atom or molecule. Hydrogen is a positive ion because it only has one electron in its outer shell instead of a pair. Oxygen has paired electrons, but because it is highly electronegative one of the outer electrons is held closer to the nucleus, creating a partial negative charge. This partial negative charge attracts the electron in the outer shell of hydrogen and creates a bond. This type of bond accounts for the high surface tension in water.</span>
