WHEN A 50.0g SAMPLE OF AN ELEMENT COMBINES COMPLETELY WITH ANOTHER ELEMENT TO MAKE 78.4g OF A COMPOUND. WHAT MASS OF THE SECOND ELEMENT REACTED? HOW TO i SOLVE THIS PROBLEM?

Thank you DrBob222!

I got it now!

To solve this problem, you need to determine the mass of the second element that reacted to form the compound. Here's how you can approach it step by step:

Step 1: Calculate the mass of the first element that did not react.
Since the total mass of the compound is 78.4g and the mass of the sample element is 50.0g, you can subtract the mass of the sample element from the total mass of the compound to find the mass of the first element that did not react.
Mass of first element = Total mass of the compound - Mass of sample element
Mass of first element = 78.4g - 50.0g
Mass of first element = 28.4g

Step 2: Calculate the mass of the second element that reacted.
Since we know that the total mass of the compound is 78.4g, we can use this information along with the mass of the first element to find the mass of the second element.
Mass of second element = Total mass of the compound - Mass of first element
Mass of second element = 78.4g - 28.4g
Mass of second element = 50.0g

Therefore, the mass of the second element that reacted is 50.0g.

See my response to your question above. Same procedure.