I think the correct answer from the choices listed above is option 1. The list that includes three forms of energy would be chemical, mechanical and electromagnetic. Pressure and temperature are not energy. Hope this answers the question. Have a nice day.
Alka-seltzer is an effervescent antacid which neutralizes the acid of the stomach by generating CO2. The chemical formula of alka-seltzer is C16H17NaO14. In this case, if we are given the mass of the antacid used, then by stoichiometry, mass alka-seltzer * (1/ molar mass of alk-selz) * (1 mol Co2 / 1 mol alk-seltz) * (44 g/molCo2). That is how you get the mass of Co2 produced.
From mole ratios, the mass ratio of different elements can be predicted. Also the volume can be predicted based on density for liquids and ideal gas law equation for gases. From the mole ratios, the empirical formula can be predicted, as well as the molecular formula given another data which is mass of the sample.
1) Write the balanced chemical equation
2HCl + Na2 CO3 ----------> 2NaCl + H2CO3
2) Write the molar ratios:
2 mol HCl : 1 mol Na2CO3 : 2 mol NaCl : 1 mol H2CO3
3) Convert 0.15g of sodium carbonate to number of moles
3a) Calculate the molar mass of Na2CO3
Na: 2 * 23 g/mol = 46 g/mol
C: 12 g/mol =
O: 3 * 16 g/mol = 48 g/mol
molar mass = 46g/mol + 12g/mol + 48g/mol = 106 g/mol
3b.- Calculate the number of moles of Na2CO3
# moles = grams / molar mass = 0.15 g / 106 g/mol = 0.0014 mol Na2CO3
4) Calculate the number of moles of HCl from the molar proportion:
[0.0014 mol Na2CO3] * [2 mol HCl / 1 mol Na2CO3] = 0.0028 mol HCl
5) Calculate the volume of HCl from the definition of Molarity
Molarity, M = # moles / volume in liters
=> Volume in liters = # moles / M = 0.0028 mol / 0.1 M = 0.028 liters
0.028 liters * 1000 ml / liter = 28 ml.
Answer: 28 mililiters of 0.1 M HCl.
