Answer:You can set up stoichiemetry using the following equation:
(15.6 g MgF2) x (38g F / 62g MgF2) x (6.022x10^23 / 19gF)
= 3.03 x 10^23 molecules of F
or 1.52 x 10^23 molecules of F2
The number of molecules of magnesium fluoride in 15.6 g of MgF2 has to be found.
The molecular mass of MgF2 is 62.3018. 15.6 g of MgF2 is equivalent to 15.6/62.3018 mole of MgF2.
One mole of a gas has 6.02214179*10^23 particles.
15.6/62.3018 mole of MgF2 has (15.6/62.3018)*6.02214179*10^23 molecules of the compound.
(15.6/62.3018)*6.02214179*10^23
=> 1.5079*20^23
If this is rounded to one decimal figure the result is 1.51*10^23.
The number of molecules of MgF2 in 15.6 g of the gas is 1.51*10^23.
The equation for energy of a photon is E=hv where v equals frequency and h equals the Planck constant (6.626X10^-34). So since you've been given frequency you can just plug in frequency to find the total energy in joules.
E=(3.55X10^17)(6.626X10^-34)
E=2.35223X10^-16
Not sure how many significant figures you needed. Hope this helped.
<u>We are given:</u>
Mass of ice = 21 grams
The ice is already at 0°c, the temperature at which it melts to form water
Molar heat of fusion of Ice = 6.02 kJ/mol
<u>Finding the energy required:</u>
<u>Number of moles of Ice: </u>
Molar mass of water = 18 g/mol
Number of moles = given mass/ molar mass
Number of moles = 21 / 18 = 7/6 moles
<u>Energy required to melt the given amount of ice:</u>
Energy = number of moles * molar heat of fusion
Energy = (7/6) * (6.02)
Energy = 7.02 kJ OR 7020 joules
For the answer to the question above, asking to w<span>rite the complete balanced equation for the reaction between aluminum metal (Al) and oxygen gas (O2)and You do not need to make the subscripts smaller.
My answer would be,
</span><span>4Al(s) + 3O2(g) --->2 Al2O3(s)
</span>
I hope this helps.
Answer:
The net ionic equation is as follows:
HCN(aq) + OH-(aq) ----> H20(l) + CN-(aq)
Explanation:
The reaction between Hydrocyanic acid, HCN, and sodium hydroxide is a neutralization reaction between a weak acid and a strong base.
Hydrocyanic acid being a weak acid ionizes only slightly, while sodium hydroxide being a strong base ionizes completely. The equation for the reaction is given below:
A. HCN(aq) + NaOH-(aq) ----> NaCN(aq) + H2O(l)
Since Hydrocyanic acid is written in the aqueous form as it ionizes only slightly and the ionic equation is given below:
HCN(aq) + Na+(aq)+OH-(aq) ----> Na+(aq)+CN-(aq) + H2O(l)
Na+ being a spectator ion is removed from the net ionic equation given below:
HCN(aq) + OH-(aq) ----> H20(l) + CN-(aq)
