Exsperements? labs? chemesty? it could be a few things...
The corect answers will be:
1) A
2) B
3) D
Hope this helped :)
Answer:
Y = 92.5 %
Explanation:
Hello there!
In this case, since the reaction between lead (II) nitrate and potassium bromide is:

Exhibits a 1:2 mole ratio of the former to the later, we can calculate the moles of lead (II) bromide product to figure out the limiting reactant:

Thus, the limiting reactant is the KBr as it yields the fewest moles of PbBr2 product. Afterwards, we calculate the mass of product by using its molar mass:

And the resulting percent yield:

Regards!
Answer:
Wavelenght is 7,79x10⁻⁵ m
Explanation:
The equation that connects wavelentgh (λ) and frequency (ν) is:
λ=c/ν
Where c is speed of light (3x10⁸ m/sec) and λ is expressed in lenght´s units and ν is expressed in "time⁻¹ " units (for example, sec⁻¹)
According to the details, if we just replace the given value of frequency, we just obtaing wavelenght data:
λ= (3x10⁸ m/sec)/(3,85x10¹² sec⁻¹) = 7,79x10⁻⁵ m