D. 18 x 10^23 is the total number of atoms in 1.0 mole of CO2
The reaction between butanoic acid and ethanol is:
CH3CH2CH2COOH + CH3CH2OH → CH3CH2CH2COOCH3CH2 + H2O
Based on the reaction stoichiometry:
1 mole of butanoic acid forms 1 mole of ethyl butyrate
Now,
Molar mass of Butanoic acid = 88.0 g/mol
Given mass of butanoic acid = 7.20 g
Therefore, # moles of butanoic acid reacted = 7.20/88.0 = 0.0818 moles
# moles of ethyl butyrate formed = 0.0818 moles
Molar mass of ethyl butyrate = 116 g/mol
Mass of ethyl butyrate synthesized = 0.0818 * 116 = 9.49 g
1) deep trenches
2) active volcanoes
3) arcs of islands along the tectonic boundaries
4) in some cases, mountain ranges
To determine the Ka of the acid, we can use the equation for the pH of weak acids which is expressed as:
pH = -0.5 log Ka
2.67 = -0.5 log Ka
Ka = 4.571x10^-6
Weak acids are acids that do not dissociate completely in solution. The solution would contain the cations, anions and the acid itself as a compound. Hope this helps.