True because certain fabric will catch on fire
It is important to take note of th temperature in determining the density of a substance because this will set as a basis and will likely be a variable in the experiment because this will also contribute on the effects of the experiment and a basis of how the experiment has turned to be that way.
The value of Q for 125.0 ml of 0.0500 m Pb(NO3)2 is mixed with 75.0 ml of 0.0200 m NaCl at 25°C is 2.11 × 10^(-6).
Aa we know that, 125mL of 0.06M Pb(NO3)2 is mixed with 75.0 ml of 0.0200 m NaCl.
Given, T = 25°C.
<h3>Chemical equation:</h3>
Pb(NO3)2 + NaCl ---- NaNO3 + PbCl2
PbCl2 in aqueous solution split into following ions
PbCl2 ------ Pb(+2) + 2Cl-
Q = [Pb(+2)] [Cl-]^2
The Concentration of Pb(+2) ions and Cl- ions can be calculated as
[Pb(+2)] = 0.06 × 125/200
= 0.0375
[Cl-] = 0.02 × 75/200
= 0.0075
By substituting all the values, we get
[0.0375] [0.0075]^2
= 2.11 × 10^(-6).
Thus, we calculated that the value of Q for 125.0 ml of 0.0500 m Pb(NO3)2 is mixed with 75.0 ml of 0.0200 m NaCl at 25°C is 2.11 × 10^(-6).
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Answer:
24 atoms of H or 1.4 x 10²⁵ hydrogen atoms
Explanation:
simple method
1 H₂O has atoms of hydrogen and 1 atom of oxygen
while 12H₂O will have 24 atoms of hydrogen and 12 atom of oxygen
by Avagadros number
molar mass of water H₂0=18.01528 g/mol
1 mole of H₂0 have 2 moles of Hydrogen
one mole of water= 6.02⋅10²³water molecules =1.2 x 10²⁴hydrogen atoms
12 mole of H₂O = 1.2 x 10²⁴ x 12= 1.4 x 10²⁵ hydrogen atoms
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1.4 x 10²⁵ hydrogen atoms in 12 moles of H₂O
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In Chemistry, when we say Group, this term refers to the column in the periodic table wherein the elements in it share the same valence electron structure, as well as their physical and chemical properties. Therefore, based on the statements above, I can say that the answer would be the first option.