Answer:
0.21 M
Explanation:
The method to solve this question is to use Beer´s law which is expressed by
A = εcl
where A is the absorbance, ε is molar absorptivity ( M⁻¹·cm⁻¹ ), c is the concentration M (mol/L), and l is the path length in cm.
Solving for c in the above equation
c = A / εl = 0.458 / ( 2.16 M⁻¹·cm⁻¹ x 1.01 cm ) =0.21 M
Note: there is an error in the units for the absorptivity constant, it should have said M⁻¹·cm⁻¹ . You can check this by realizing the absorbance is unitless and when we multiply M⁻¹·cm⁻¹ with the units of concentration c (M) and path length (cm ) the units cancel.
54.936 grams of NaCl will be produced from 33.0 g of Na and 34.0 g of Cl.
Explanation:
Data given:
mass of Na = 33 grams
mass of 
= 24 grams
atomic mass of Na = 23 grams/moles
atomic mass of Cl = 70 grams/mole
mass of NaCl formed =?
atomic mass of NaCl = 58.44 gram/mole
balanced chemical reaction:
2Na + ⇒ 2NaCl
number of moles = 
putting the values in the equation:
number of moles of Na = 
= 0.69 moles
number of moles of chlorine gas = 
= 0.47 moles
limiting reagent is chlorine gas in the reaction
from the balanced chemical reaction:
1 mole of chlorine gas reacts to form 2 moles of NaCl
then 0.47 moles of chlorine gas will form x moles
= 
x = 0.94 moles of NaCl is formed.
mass = atomic mass x number of moles
mass = 58.44 x 0.94
= 54.936 grams of NaCl is produced.
The chemical symbol for gold is AU
Answer:
3.38 moles.
Explanation:
The following data were obtained from the question:
Mass of copper (Cu) = 215 g
Number of mole of copper (Cu) =...?
The number of mole of copper (Cu) in 215 g can be obtained as follow:
Mass of copper (Cu) = 215 g
Molar mass of copper (Cu) = 63.55 g/mol
Number of mole of copper (Cu) =...?
Mole = mass /Molar mass
Mole of Cu = 215/63.55
Mole of Cu = 3.38 moles
Therefore, 3.38 moles of copper (Cu) is present in the sample.
B Aipo, is insoluble in water
