how many moles are in 9.8 grams of calcium?
According to mole concept, there are 0.245 moles in 9.8 grams of calcium.
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Number of moles=mass/molar mass=9.8/40=0.245 moles.
Learn more about moles,here:
#SPJ6
NaOH = 40.0 g/mol) _M
The molarity of 6.00 liters of an aqueous solution that contains 80g of sodium hydroxide is 0.33M.
Molarity = no. of moles ÷ volume
Molarity = 2mol ÷ 6L
Molarity = 0.33M
Therefore, the molarity of 2.0 liters of an aqueous solution that contains 0.50 mol of sodium hydroxide is 0.33M.
Learn more about molarity at: brainly.com/question/2817451
For example,
"Which of the following molecules is expected to have one or more unpaired electrons? Check all that apply.
O2-
F2+
N22-
O22-"
Any help would be appreciated. ...?
To determine unpaired electrons, look at the valence electrons in an ion's molecule, accounting for extra or absent electrons due to the ion's charge. For instance, O2- and F2+ have one unpaired electron, but N22- is not a valid ion, and O22- electrons are all paired.
To determine if a molecular ion will have one or more unpaired electrons, we need to look at the number of valence electrons in the molecule and take into account any extra or absent electrons due to the charge of the ion.
For example, O2- has 12 + 1 = 13 valence electrons (6 from each oxygen atom and 1 extra due to the negative charge). It requires 14 for all the electrons to be paired (2 in each oxygen's inner shell and 4 bonds or lone pairs in the outer shell), thus there is one unpaired electron in O2-.
However, in F2+, there are only 13 electrons because one electron is lost due to the positive charge. Like oxygen, fluorine also prefers to have 7 electrons in its outer shell, so there are also unpaired electrons in F2+.
N22- doesn’t exist because nitrogen normally forms triple bond and doesn’t need or want to take extra electrons, so this molecular ion is not valid.
O22- has 14 + 2 = 16 valence electrons and this total number of valence electrons is an even number, which indicates all the electrons are paired.
#SPJ3
Answer
solids conduct heat more efficiently ! basically their particles are more tightly packed and stay in that position, so the heat transfer by collision allows for the best conduction
Explanation:
hope this helps ! :)