Molarity= moles/ liters
first you need to calculate the moles using the molar mass of the molecule to convert grams to moles
molar mass MgO= 40.3 grams/ mole
62.5 gram MgO (1 mole/ 40.3 grams)= 1.55 mole
Molarity= 1.55 mole/ 1.50 Liters= 1.03 M
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.
Answer
Because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. So, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.
Explanation:
When the body senses foreign substances (called antigens), the immune system works to recognize the antigens and get rid of them. B lymphocytes are triggered to make antibodies (also called immunoglobulins). These proteins lock onto specific antigens.
