Answer:
Option 4 is the right of ur question
Explanation:
The electronic configuration of an atom can be represented by either sublevel notation or using shell notations.
Sublevel notations shows the sequence of filling electrons into the orbitals of the sublevels.
Shell notations are used to denote the electrons in all orbitals of each energy level.
Element Number of electrons Sub-level notation shell notation
Mg 12 1s² 2s² 2p⁶ 3s² 2 8 2
A technician mixes 80 ml of a 5% solution with 10 ml of water. the final percentage strength of the solution prepared is 40 %.
given that :
8 ml of a 5 % solution mix with 10 ml . that means the 80 mL of 5 % solution is diluted with water of 10 mL
therefore, 80 × 5 = 10 × x %
x % = 40 %
Therefore, the final percentage strength of the solution is 40 %
Thus, A technician mixes 80 ml of a 5% solution with 10 ml of water. the final percentage strength of the solution prepared is 40 %.
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<span>Even surfaces that seem smooth have different bumps that you could see with a microscope, so friction occurs even with smooth-looking objects.</span>
Answer:
43.13Kg of melamine
Explanation:
The problem gives you the mass of urea and two balanced equations:
First we need to calculate the number of moles of urea that are used in the reaction, so:
molar mass of urea =
The problem says that you have 161.2Kg of urea, so you take that mass of urea and find the moles of urea:
161.2Kg of urea2684 moles of urea
Now from the stoichiometry you have:
2684 moles of urea = 447 moles of melamine
The molar mass of the melamine is so we have:
= 5637.64 g of melamine
Converting that mass of melamine to Kg:
5637.64 g of melamine * = 56.38 Kg of melamine, that is the theoretical yield of melamine.
Finally we need to calculate the mass of melamine with a yield of 76.5%, so we have:
%yield = 100*(Actual yield of melamine / Theoretical yield of melamine)
Actual yield of melamine = = 43.13Kg of melamine