Answer:
22.2 g of MgF₂
Explanation:
We star from the reaction:
NaF → sodium fluoride
Mg → Magnesium
2NaF + Mg → MgF₂ + 2Na
2 moles of sodium fluoride react to 1 mol of Mg in order to produce 1 mol of magnesium fluoride and 2 moles of sodium.
We convert mass of the reactant to moles:
30 g . 1mol / 41.98 g = 0.715 mol
We assume that Mg is in excess
As ratio is 2:1, if we have 0.715 moles of NaF we may produce the half of moles, of MgF₂
0.715 mol /2 = 0.357 moles of MgF₂
We convert moles to mass: 0.357 mol . 62.30g /mol = 22.2 g
The number of protons, neutrons, and electrons that iron (Fe) have if it has a +4 charge are 26, 29 and 22 respectively.
<h3>How to calculate proton, electron and neutron numbers?</h3>
Atomic number of an element is the number of protons in the atom of that element. The number of protons of a neutral atom i.e. charge 0 is equal to the number of electrons.
Iron is a metallic chemical element having atomic number 26 and symbol Fe. Since the atomic number is 26, the number of protons is 26.
If the charge of the iron is +4, this means that the number of protons will be 26 while the number of electrons will be 22. The number of protons will be 55 - 26 = 29.
Learn more about proton number at: brainly.com/question/28992636
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The answer is <span>b. 1% H, 42% Cl, 57% O.</span>
Let's first calculate a molar mass (M) of HClO₃. <span>Molar mass is a mass of 1 mole of a substance. It can be expressed as the sum of relative atomic masses (Ar), which are masses of atoms of the elements:
</span>M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O)
Ar(H) = 1 u
Ar(Cl) = 35.5 u
Ar(O) = 16 u
M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O) = 1 + 35.5 + 3 · <span>16 = 84.5 u
Now, we just need to calculate mass percent of each element using the proportion:
Ar : x = M : 100% </span>⇒ x = Ar ÷ M · 100%
Hydrogen: x = Ar(H) ÷ M · 100% = 1 ÷ 84.5 · 100% = 1.2% ≈ 1%
Chlorine: x = Ar(Cl) ÷ M · 100% = 35.5 ÷ 84.5 <span>· 100% = 42%
</span>Oxygen: x = 3Ar(O) ÷ M · 100% = 48 ÷ 84.5 · 100% = 56.8% ≈ 57%
Answer:
atoms are bonded with a single bond one double bond
One way of expressing concentration is by molarity. It is the amount of solute per unit volume of the solution. Usually, it takes the unit mol/L. The calculation for this problem is as follows:
1.02 mM = (1.02 mol / mL) (2.0 mL) = 2.04 mol
Thus, the solution has 2.04 mol of glucose.