Answer:
250mL
Explanation:
The first step in this kind of question is to balance the chemical equation:
Na₂CO₃ + 2HCl → CO₂ + H₂O + 2NaCl
The question asks to figure out how many mL of the reactant Na₂CO₃ are required to produce 11.2 L of CO₂ . To solve this we will use the molar ratio between these two chemical species, that is <em>how many moles of Na₂CO₃ are required to produce one mol of CO₂.</em> We answer this by looking at the equation: the molar ratio is 1 to 1.
So first we need to convert the 11.2 L at STP of CO₂ to moles. CO₂ is a gas and STP means standard temperature and pressure (0°C and 1 atm). The volume of one mol of gas at STP is 22.4 L. So we can convert the 11.2 L to moles using this value:
Now that we know how many moles of CO₂ are produced, we can calculate the moles of Na₂CO₃ required using the molar ratio 1:1. To produce one mol of CO₂ we need one mol of Na₂CO₃, hence to produce 0.5 moles of CO₂ we need 0.5 moles of Na₂CO₃.
Now, the question asks how many mL of a 2M solution of Na₂CO₃ are required. M stands for molarity which is a concentration unit meaning moles per liter, hence, <em>2M means 2 moles per liter of solution</em> (which means in 1000mL of solution there are 2 moles of Na₂CO₃ because 1L=1000mL). So knowing this we must calculate in how many mL of the solution there are 0.5 moles of Na₂CO₃:
0.5 mol Na₂CO₃ × = 250 mL
250 mL of a 2M solution of Na₂CO₃ are required to produce 11.2 L of CO₂ at STP
Answer:
A
Explanation:
it has non polar molecule, because it has the equal sharing of electrons, so equal repulsion from all sides. atoms are equally represented.
Homogeneous mixture of tow or more substances. Solution (im not sure though)
A. all magnets have two poles