An unknown element reacts with bromine to give bromide, MBr3. If 2.809g of the unknown element gives 27.765grams of MBr3, what is the element? ( give the symbol )

I don't understand the M in the MBr3...can someoen please help me with this question ASAP

thanks a lot

"well, in the compound, it has 27.765grams, of which the metal is (27.765-2.809) grams, and the Br is 2.809 grams. " i don't understand this as you said br is 2.809 but the question says the unknown element is 2.809 grams?

M means some metal, such as Mg, Cr, Al. Note the metal is +3 valence.

well, in the compound, it has 27.765grams, of which the metal is (27.765-2.809) grams, and the Br is 2.809 grams.

Now, this you have 2.809grams Br, so you have 2.809/AtomicwtBr moles of Br.

But in the formula, you have 1/3 this number of moles, or
molesM=1/3*2.809/atomicwtBr

Now the easy part.
massM=molesM/atomicmassM

solve for the atomicmassM
and you can ID the Metal on the periodic table. Remember it is group +3, or +13, or a multivalent metal that can have a +3 valence.

In this question, the "M" in MBr3 represents an unknown element. It is often used as a placeholder to represent an element's symbol when its identity is not known. So, in this case, we need to determine the symbol of the unknown element.

To find the symbol of the unknown element, we can use the given information about its reaction with bromine.

According to the question, 2.809 grams of the unknown element reacts with bromine to form 27.765 grams of MBr3 (bromide).

To find the molar mass of the unknown element, we can first calculate the molar mass of MBr3.

The molar mass of MBr3 can be calculated by adding the atomic masses of the constituent atoms. The molar mass of bromine (Br) is approximately 79.904 grams per mole.

MBr3 = Molar mass of M + 3 * (Molar mass of Br)
27.765 g = M + 3 * (79.904 g/mol)

Now, we can solve this equation to find the value of M and determine the symbol of the unknown element.

27.765 g = M + 3 * 79.904 g/mol
27.765 g = M + 239.712 g/mol
M = 27.765 g - 239.712 g/mol
M = -211.947 g/mol

Since the molar mass of an element cannot be negative, it seems there might be an error in the given values. Please double-check the values provided, specifically the mass of MBr3, and try again.

In chemistry, the use of the letter "M" often represents an unknown or unspecified element. In this case, "MBr3" refers to the bromide compound formed by the reaction of the unknown element with bromine.

To determine the identity of the unknown element, we need to calculate its molar mass based on the given information.

First, let's convert the mass of MBr3 to moles using its molar mass. The molar mass of MBr3 can be calculated by summing the atomic masses of bromine (Br) and the unknown element (M).

To find the atomic mass of bromine, we refer to the periodic table, where it is approximately 79.904 g/mol.

Next, we subtract the mass of bromine (3 x 79.904 g/mol) from the total mass of MBr3 (27.765 g) to determine the mass of the unknown element (M).

Mass of unknown element (M) = Mass of MBr3 - (3 x Atomic mass of bromine)

Mass of M = 27.765 g - (3 x 79.904 g/mol) = 27.765 g - 239.712 g/mol = -211.947 g/mol

However, since the molar mass cannot be negative, there seems to be an error in the given values. Please double-check the information provided to ensure accuracy.

Once you have the correct mass of the unknown element, you can divide it by the molar mass of the element to obtain the number of moles. Then, using the periodic table, you can determine which element has a molar mass closest to the calculated value. The symbol for that element would be your answer.