Chemistry, 04.07.2019 04:00 keigleyhannah30

The mass of 0.3253 mol of a compound with the formula mbr4, in which m is a metallic element, is 171.4 g. what is the identity of the metal

Answers: 1

Show answers

Answers

Lead (Pb) Let's figure out how many moles of the unknown element there is and what it's atomic weight is. We have 0.3253 mol of mBr4 which has a mass of 171.4 g. Since there's 4 bromine atoms per molecule, that means we have 4 * 0.3253 = 1.3012 moles of bromine. The atomic weight of bromine is 79.904, so 1.3012 mol * 79.904 g/mol = 103.9711 g So now subtract the known mass of bromine from the mass of the unknown substance. 171.4g - 103.9711g = 67.42892 g Now divide that by the number of moles we have of that metal to determine its atomic weight 67.42892 g / 0.3253 mol = 207.2822 g/mol Now look at the periodic table to see if there's any metals with an atomic weight close to 207.2822 g/mol The closest match is for Lead (Pb) with an atomic weight of 207.2. Additionally, it's in the same column as Carbon so Lead has 4 valance electrons. And Bromine wants to grab one electron so you'd expect lead to combine with 4 bromine atoms. Which this compound does. So the evidence indicates that the unknown metal is Lead.

Answer from: Quest

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is $1s^{2}2s^{2}2p^{6}3s^{1}$ and electronic configuration of phosphorous is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}$ .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

$3na + p \rightarrow na_{3}p$

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

Electrons are transferred from atoms of to atoms of this transfer makes the sodium atoms and the

Answer from: Quest

the correct answer to this question is 2

Another question on Chemistry

Chemistry, 22.06.2019 07:00

The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle what is the common name for the group to which this organism belong

Answers: 3

Answer

Chemistry, 22.06.2019 08:00

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely.analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?

Answers: 1

Answer

Chemistry, 22.06.2019 08:00

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

Answers: 1

Answer

Chemistry, 23.06.2019 00:00

How do you determine the percent yield of a chemical reaction

Answers: 1

Answer

You know the right answer?

The mass of 0.3253 mol of a compound with the formula mbr4, in which m is a metallic element, is 171...

Questions