the mass of 2.50 mol of a compound with the formula ECl4, in which E is a nonmetallic element, is 385g. what is the molar mass of Ecl4? what is the identity of E?

Answered in another post.

To find the molar mass of ECl4 and determine the identity of E, we need to calculate the molar mass of the entire compound and then deduce the molar mass of E.

Step 1: Find the molar mass of the entire compound ECl4.
The molar mass of a compound is the sum of the molar masses of each element in the formula. Let's start by finding the molar mass of ECl4.

First, we need to determine the molar mass of Cl (chlorine). The atomic mass of chlorine (Cl) is 35.45 g/mol. Since there are four Cl atoms in ECl4, the total contribution to the molar mass from chlorine is: 4 * 35.45 g/mol = 141.8 g/mol.

Step 2: Determine the molar mass of E.
Since the total molar mass of the compound (ECl4) is given as 385 g/mol, and we have already accounted for the molar mass of Cl, we can find the molar mass of E by subtracting the molar mass of Cl from the total molar mass.

Molar mass of E = Total molar mass of ECl4 - Molar mass of Cl
Molar mass of E = 385 g/mol - 141.8 g/mol = 243.2 g/mol

Therefore, the molar mass of ECl4 is 385 g/mol, and the molar mass of E is 243.2 g/mol.

Now, based on the periodic table, we can look for an element that has a molar mass of approximately 243.2 g/mol. According to the periodic table, the closest match is the element Te (tellurium), as its molar mass is 127.6 g/mol. Therefore, E in the compound ECl4 represents tellurium (Te).

In conclusion, the molar mass of ECl4 is 385 g/mol, and the identity of E is tellurium (Te).