The double replacement reaction between calcium nitrate (Ca(NO3)2) and potassium oxide (K2O ) is shown below: Ca(NO3) 2 + K2 O → CaO + KNO3
How many grams of potassium oxide would be needed to produce 5.00 g of potassium nitrate (KNO3) ?

Mass = 2.355 g

Explanation:

Given data:

Mass of K₂O needed = ?

Mass of KNO₃ produced = 5.00 g

Solution:

Chemical equation:

K₂O + Ca(NO₃)₂     →   CaO +  2KNO₃

Number of moles of KNO₃:

Number of moles = mass/molar mass

Number of moles = 5.00 g/ 101.1 g/mol

Number of moles = 0.05 mol

now we will compare the moles of KNO₃ and K₂O.

                KNO₃           :             K₂O

                   2                :               1

                  0.05           :           1/2×0.05 = 0.025 mol

Mass of potassium oxide needed in gram:

Mass =  number of moles × molar mass

Mass = 0.025 mol × 94.2 g/mol

Mass = 2.355 g

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.