<u>Answer:</u> Zinc will react with lead (II) nitrate solution.
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.
General equation for single displacement reaction follows:

When zinc is reacted with calcium nitrate, the reaction does not take place as zinc is less reactive than calcium. Zinc lies below in the series than calcium.

But, when zinc is reacted with lead (II) nitrate, the reaction do take place as zinc is more reactive than lead. Zinc lies above in the series than lead.
The chemical equation for the reaction of zinc and lead (II) nitrate follows:

Hence, zinc will react with lead (II) nitrate solution.
Answer:
129,600kg/day
Explanation:
The river is flowing at 30.0
1
= 1000L
Multiply by 1000 to convert to L/s
flowrate of river = 30*1000 =30,000L/s
Convert L/s to litre per day by multiplying by 24*60*60
flowrate of river = 30,000 * 24*60*60 L/day
= 2,592,000,000L/day
if the river contains 50mg of salt in 1L of solution
lets find how many mg of salt (X) is contained in 2,592,000,000L/day
X= 
X= 129,600,000,000 mg/day
convert this value to kg/day by multiply by 
X= 129,600kg/day
Answer:
40.3∘C
Explanation:
At planet B;
Water boils = 180∘C
Water freezes = 50∘C
In this planet the temperature difference = 180 - 50 = 130 compared to earth where the temperature difference is; 100 - 0 = 100
This means;
130 ∘C = 100 ∘C
x ∘C = 31 ∘C
x = 31 * 130 / 100
x = 40.3∘C
Answer:
molecular weight (Mb) = 0.42 g/mol
Explanation:
mass sample (solute) (wb) = 58.125 g
mass sln = 750.0 g = mass solute + mass solvent
∴ solute (b) unknown nonelectrolyte compound
∴ solvent (a): water
⇒ mb = mol solute/Kg solvent (nb/wa)
boiling point:
- ΔT = K*mb = 100.220°C ≅ 373.22 K
∴ K water = 1.86 K.Kg/mol
⇒ Mb = ? (molecular weight) (wb/nb)
⇒ mb = ΔT / K
⇒ mb = (373.22 K) / (1.86 K.Kg/mol)
⇒ mb = 200.656 mol/Kg
∴ mass solvent = 750.0 g - 58.125 g = 691.875 g = 0.692 Kg
moles solute:
⇒ nb = (200.656 mol/Kg)*(0.692 Kg) = 138.83 mol solute
molecular weight:
⇒ Mb = (58.125 g)/(138.83 mol) = 0.42 g/mol