Molar mass :
NaBr = 103 g/mol
Pb(NO3)2 = 331.20 g/mol
<span><span /><span>Balanced chemical equation :
</span></span>2 NaBr + 1 Pb(NO3)2 = 2 NaNO3 + 1 PbBr<span>2
</span><span>
2*103 g NaBr ------------> 1 * 331.20 g Pb(NO3)2
g NaBr -------------------> 311 g Pb(NO3)2
331.20 g = 2*103*311
331.20 g = 64066
mass ( NaBr ) = 64066 / 331.20
mass ( naBr) = 193,43 g of NaBr
hope this helps!.
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Let's start with the amount given in percent. Let our basis be 100 grams of compound. So, that means that in this amount, 57.1 g is oxygen and 100-57.1=42.9 g is carbon. Since there is 1:1 atom ratio, it also means that moles oxygen = moles carbon.
Moles = Mass/Relative Mass
Let x be the relative mass of oxygen
57.1/16 = 42.9/x
Solving for x,
<em>x = 12.02 amu</em>
Answer:
The value of the equilibrium constant for the reaction A ⇒ B is Kc = 1.72 × 10³.
The value of the equilibrium constant for the reaction B ⇒ A is K'c = 5.81 × 10⁻⁴.
Explanation:
For the reaction A ⇒ B, the equilibrium constant (Kc) is equal to the forward rate constant (kf) divided by the reverse rate constant (ki).

If we consider the inverse reaction B ⇒ A, its equilibrium constant (K'c) is the inverse of the forward reaction equilibrium constant.

Remember....
mass number= atomic number + number of neutrons
If the mass number is 19 and the atomic number is 9, then the number of neutrons is 19-9 which is 10.
There appears to be no table shown, but I can still answer. Aluminum has 3 valence electrons