1. Combine equations 1,2,3 to obtain equation 4. Then provide an equation for calculating the heat of reaction in kJ/mol. Equation 1: MgO(s)+2HCl(aq)--->MgCl2(aq)+H2O (l)

Equation 2: Mg(s)+2HCl(aq)>MgCl2(aq)+H2(g)
Equation 3: H2(g)+1/2O2(g)>H2O(l)

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate