Answer: 0.335 moles
Explanation:
Given that,
Amount of moles of KBr solute (n) = ?
Volume of KBr solution (v) = 0.67 L
Concentration of KBr solution (c) = 0.50M
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
make n the subject formula
n = c x v
n = 0.50M x 0.67L
n = 0.335 moles
Thus, there are 0.335 moles of KBr in 0.67 L of a 0.50 M KBr solution
Answer:
1. The dye that absorbs at 530 nm.
Explanation:
The dye will absorb light to promote the transition of an electron from the HOMO to the LUMO orbital.
The higher the gap, the higher the energy of transition. The energy can be calculated by E = hc/λ, in which h and c are constants and λ is the wavelength.
The equation shows that the higher the energy, the higher the gap and the lower the wavelength.
Therefore, the dye with absorption at 530 nm has the higher HOMO-LUMO gap.
Fossil fuels because easy to transport
<span>1.67 x 10^-3 moles
Calculate the molar mass of C9H8O4
Carbon = 12.0107
Hydrogen = 1.00794
Oxygen = 15.999
C9H8O4 = 9 * 12.0107 + 8 * 1.00794 + 4 * 15.999 = 180.1558
Now divide the mass you have by the molar mass
0.300 g / 180.1558 g/mole = 1.665225 x 10^-3
Round to 3 significant figures
1.67 x 10^-3</span>