Consider the following hypothetical aqueous reaction: A1aq2S B1aq2. A flask is charged with 0.065 mol of A in a total volume of 100.0 mL. The following data are collected: Time (min) 0 10 20 30 40 Moles of A 0.065 0.051 0.042 0.036 0.031 (b) Calculate the average rate of disappearance of A for each 10-min interval in units of M>s.

Video transcript

Hi everyone for this problem. It reads given a hypothetical acquis reaction, a solution of 0.78 moles of C. And a total volume of 200 mL was made in a flask the moles of C for every 10 minutes were recorded, calculate the average rate in molar per second of the disappearance of C. And the solution for each time recorded with the assumption that there is only see initially and no molecule of D. And that the reaction does not have an intermediate. Okay so our goal for this problem is to calculate the average rate and molar per second. So let's start off by looking at our multiple ratio of C two D. So our reactant to product. So this multiple ratio is 1-1. Okay and let's recall that our concentration of C concentration is mole per leader. So our change in concentration is going to equal mole of C. Final minus more of C. Initial. So this is what we're going to be looking for. And let's start off with tea is 10 minutes. Okay, so at T. Is 10 minutes. We need to convert this two seconds. Okay, so in one minute We have 60 seconds. So this is going to cancel out our minutes here and we have our time and seconds of 600 seconds. Alright, so let's go ahead and find out our concentration of c. Because we know concentration is moles per leader. So our concentration for C. So let's convert our volume two leaders because we need that in leaders. So we're told our volume is 200 mL. So in one leader There's male leaders. So we need to make sure our units cancel. So our volume and middle and leaders is going to be 0. leaders. And we know how many moles. We're starting off with zero at 10 minutes at 0.062. So because concentration is in moles per leader, we have 0.062 moles divided by 0.2 leaders gives us 0. molar. That's our concentration moles per liter. So up above we set our concentration of C is going to equal our final volume minus our initial volume. Okay, so our change and concentration for C is going to be our final more. Final is zero. Our final is 0.31. That's what we just calculated. So we have 0.31 minus more initial and our mole initial is 0.39. So this gives us 0.08. So our rate is going to equal negative change in concentration of C over seconds because our concentration of reactant is decreasing. So we'll have a negative. So we have our change in concentration is going to be negative. 0.8 molar over our Secondf. seconds. And this is going to give us a final answer of 1. times 10 to the negative four Moeller per second. Okay, so this is going to be our average rate. Okay, That's the end of this problem, and that's the answer to this problem. I hope this was helpful.