Ive been trying to do my chemistry homework for the past few hours and I keep getting some of the questions wrong. These are the 2 questions i am having trouble with.
1.
If 0.582 L of gaseous CO2 measured at STP dissolved in 920 mL of water is produced stoichiometrically according to the balanced equation in a reaction solution with a total volume of 1800 mL, what is the molarity (M) of Na+ produced?
Na2CO3(aq) + 2 HCl(aq) �¨ CO2(g) + 2 NaCl(aq) + H2O(l)
Molar Mass (g)
CO2 44.010
Na+ 22.989
Molar Volume (L)
22.400 at STP
Gas Constant
0.0821
2.If 1.15 g of solid MnS and 800 mL of 0.0288 M aqueous HCl are reacted stoichiometrically according to the equation, how many mol of solid MnS remained?
MnS(s) + 2HCl(aq) �¨ H2S(g) + MnCl2(aq)
Molar Mass (g)
HCl 36.461
MnS 87.00
Molar Volume (L)
22.400 at STP
Gas Constant
0.0821
#1 is worded so poorly I don't understand it. My biggest problem is that I don't know what volume the CO2 is dissolved in; e.g., is CO2 dissolved in 920 or in 1800 or is it 920+1800 mL?
#2.
Determine mols MnS by 1.15/87.00 = ??
Determine mols HCl by M x L = 0.800 x 0.0288 = ??
Determine which is the limiting reagent. I expect it is HCl (at least I'm assuming that).
Determine how much of the HCl will react with the MnS. It will be 1/2 of the mols HCl, then subtract that from mols MnS initially and multiply the difference by 87 to obtain the mass MnS remaining. I ignored any H^+ produced by H2S. Check my thinking. Check my typing for typos.
To solve these questions, we need to use stoichiometry and the concept of molarity. Here's how you can approach each question:
1. To find the molarity (M) of Na+ produced in the reaction, you need to first determine the number of moles of CO2 produced using the given volume at STP (0.582 L). Since 1 mole of any gas occupies 22.400 L at STP, you can use the molar volume to convert the volume of CO2 to moles.
Number of moles of CO2 = Volume of CO2 (L) / Molar Volume of CO2 at STP (L/mol)
Next, you need to use the balanced equation to determine the stoichiometric ratio between CO2 and Na+ ions. From the equation, you can see that 1 mole of CO2 produces 2 moles of Na+. Therefore, you can multiply the number of moles of CO2 by the stoichiometric ratio to find the number of moles of Na+.
Number of moles of Na+ = Number of moles of CO2 * Stoichiometric ratio
Finally, you can use the molarity formula to calculate the molarity of Na+.
Molarity (M) = Number of moles of Na+ / Volume of reaction solution (L)
Plug in the values you calculated to get the final answer.
2. To find the number of moles of solid MnS that remained, you need to first determine the number of moles of HCl using its molarity (0.0288 M) and the given volume (800 mL). Remember that molarity is defined as moles of solute per liter of solution. So, you can use the molarity formula to calculate the number of moles of HCl.
Number of moles of HCl = Molarity (M) * Volume of HCl (L)
Next, you need to use the balanced equation to determine the stoichiometric ratio between MnS and HCl. As per the equation, 1 mole of MnS reacts with 2 moles of HCl. Therefore, you can use the stoichiometric ratio to calculate the number of moles of MnS that reacted.
Number of moles of MnS reacted = (Number of moles of HCl) / (Stoichiometric ratio with MnS)
Finally, subtract the number of moles of MnS reacted from the initial moles of MnS to find the number of moles of MnS that remained.
Number of moles of MnS remaining = Initial number of moles of MnS - Number of moles of MnS reacted
Substitute the given values into the equations to solve for the final answer.