Answer : The de Broglie wavelength will be 
Solution :
The formula used for de Broglie wavelength is:
..........(1)
where,
= wavelength = ?
h = Planck's constant = 
m = mass = 1.2 g = 0.0012 kg
Conversion used : 1 kg = 1000 g
v = velocity = 150 m/s
Now put all the given values in equation 1, we get:


Therefore, the de Broglie wavelength will be 
Answer:
3.62moles
Explanation:
First let us generate a balanced equation for the reaction
2Na + Cl2 —> 2NaCl
Molar Mass of Na = 23g/mol
Mass of Na from the balanced equation = 2 x 23 = 46g
Molar Mass of NaCl = 23 + 35.5 = 58.5g/mol
Mass of NaCl from the balanced equation = 2 x 58.5 = 117g
From the question,
46g of Na produced 117g of NaCl.
Therefore, 83g of Na will produce = (83 x 117)/46 = 211.11g of NaCl
Converting this mass (211.11g of NaCl) to mole, we obtain:
n = Mass /Molar Mass
n = 211.11/ 58.5
3.62moles
Answer:

Explanation:
Let's call the unknown compound X.
1. Calculate the mass of each element in 1.23383 g of X.
(a) Mass of C

(b) Mass of H

(c)Mass of Fe
(i)In 0.4131g of X

(ii) In 1.2383 g of X

(d)Mass of O
Mass of O = 1.2383 - 0.632 07 - 0.074 157 - 0.195 67 = 0.336 40 g
2. Calculate the moles of each element

3. Calculate the molar ratios
Divide all moles by the smallest number of moles.

4. Round the ratios to the nearest integer
C:H:O:Fe = 15:21:1:6
5. Write the empirical formula

Answer:
The volume would be; 136.17 ml
Explanation:
Volume V1 = 150 mL
Temperature T1 = 20°C + 273 = 293 K
Pressure P1 = 758 - 17.54 = 740.46 torr
At STP;
Volume V2 = ?
Pressure P2 = 760 torr
Temperature T2 = 273 K
Using the general gas equation;
P1V1 / T1 = P2V2 / T2
Making V2 subject of formulae;
V2 = P1V1T2 / T1P2
Inserting the values we have;
V2 = 740.46 * 150 * 273 / 293 * 760
V2 = 136.17 ml
9260 + 3240= 12,500
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