Answer:
a
The expected value is = 39 units
The standard deviation is = 0.1212 unites
b
The probability is = 0.2047 units
Explanation:
The explanation of this answer is shown on the first uploaded image
Answer:

Explanation:
Mole ratio


Moles of CO₂

Use formula to find mass

Relative molecular mass of CO₂ = 12 + 16 × 2 = 44


I think it’s c I could be wrong
Explanation:
a. Magnesium oxide is used mainly in soil treatment and groundwater remediation, wastewater treatment, etc. it is used for it's acid buffering capacity and effectiveness in dissolving heavy metals.
b. MgO is the chemical equation for the reaction.
c. multiply the given mass of O2 by the inverse of it's molar mass. multiply the molar ratio (from the balanced equation) between O2 and MgO. Multiply by the molar mass of MgO. 32g O2 x 1 mol O2 ... 32g O2 x 2mol MgO 1mol O2 x 40g MgO. .... 1mol MgO = 80 g.
d. Mg (s) + 2 HCl (aq) produces MgCl 2(aq) + H 2 (g). Where the letter "s" stands for solids, and "g" is for gas and "aq" represents aqueous solution.