Answer:
ε = 201.5
Explanation:
Given data-
mass of benzene = 25.8 mg
= 25.8×10^-3 kg
Atomic mass of benzene= 78.11 amu
volume of hexane = 250.00 ml = 0.2500 L
Absorbance = 0.266
Length of the cell = 1.00 cm
Hence concentration =
solving we get
= 0.00132 M
Formula:
A= εcl
A= absorbance
c= concentration and l= length of cell
now substituting values in the above formula
0.266= ε×0.00132×1.000
⇒ε =
⇒ε = 201.5
To find the formulae, you must add as many of the ions together to get a neutral charge. For example, one Li^+ ion and one NO2^- ion give LiNO2, which is lithium nitrite, but since CO3^2- has a charge of -2, it needs 2 Li^+ ions to make the neutral compound Li2CO3, lithium carbonate. Similarly, Cu^2+ needs 2 NO2^- ions to make the neutral compound Cu(NO2)2, copper(II) nitrite. To name these, simply add together the names of the ions used. Li^+ is lithium, Cu^2+ is copper(II), and Ba^2+ is barium. The negatively charged ions are named as nitrite for NO2^-, carbonate for CO3^2-, bisulfate for HSO4^- and phosphate for PO4^3-.
Na₃PO₄(aq)+AlBr₃(aq)→3NaBr(aq)+AlPO₄(s)
This is a double replacement reaction. You can tell that there has to be 3NaBr molecules since there are 3 Na atoms in sodium phosphate and 3 Br atoms in aluminum bromide. We also know that Na has an oxidation number of +1 which means PO₄ needs to have an oxidation number of -3 while Br has an oxidation number of -1 which means Al has an oxidation number of +3. That means that Al³⁺ and PO₄³⁻ can from AlPO₄
I hope this helps. Let me know if anything is unclear.
Answer:
Mole of the H2O = 4.5
Number of molecules =4.5 multipled by avogadro's number.
Answer:
a) 2.91%
b) 90.5 grams
Explanation:
Mass percentage is
mass%=
a) the mass of NaCl = 1.50g
The mass of water = 50.0 g
Total mass =1.5+50=51.50 g
mass% = %
b) the mass percent of NaOCl = 3.62 %
It means the mass of NaOCl in 100g of bleaching solution 3.62 g
so mass of NaOCl in 2.50kg = 0.0905 kg = 90.5g