Answer:
A. Students made a measurement error, because ending with more products is impossible.
Explanation:
The law of conversation of matter tells us that in a chemical reaction, matter is never created or destroyed, it's simply converted from one form to another. So the mass of reactants should always equal the mass of the products in a chemical reaction. If there is excess mass in the product, the students have made an error of some kind.
Answer:
50 mg.
Explanation:
From the prescription, 240 ml amount is to be prepared containing 30 ml tussin syrup. As the frequency is 5 mL qid, it means 5mL of syrup is to be administered four times daily i.e. 20 mL daily. To calculate the amount of tussin taken daily,
<em> </em><em><u>30 mL tussin</u></em><em> = </em><em><u>X mL of tussin</u></em>
<em> 240 mL solution 20ml solution</em>
⇒ 2.5 mL of tussin
5 ml tussin contains 100mg guafenesin,
So,
⇒ 2.5 ml of tussin contains 100x2.5/5 = 50 mg guaifenesin
The molar mass of this equation is 98.04
Answer:
D or the 4th one
Explanation:
mass is literally the measure of matter in an object which is essentially the weight or how much stuff there is.
Hello!
The reaction between HBr and KOH is the following:
HBr+KOH
→H₂O + KBr
To calculate the amount of HBr left after addition of KOH, you'll use the following equations:
![HBr_f=HBr_i-KOH=([HBr]*vHBr)-([KOH]*vKOH) \\ \\ HBr_f=(0,25M*0,64L)-(0,5M*0,32L)=0 mol HBr](https://tex.z-dn.net/?f=HBr_f%3DHBr_i-KOH%3D%28%5BHBr%5D%2AvHBr%29-%28%5BKOH%5D%2AvKOH%29%20%5C%5C%20%20%5C%5C%20HBr_f%3D%280%2C25M%2A0%2C64L%29-%280%2C5M%2A0%2C32L%29%3D0%20mol%20HBr)
That means that after the addition of 32 mL of KOH, there is no HBr left in the solution and the pH should be
neutral, close to 7.
Have a nice day!