Answer is: nickel (Ni) is the most active metal.
Chemical reaction 1: Pb(NO₃)₂(aq) + Ni(s) → Ni(NO₃)₂(aq) + Pb(s).
Chemical reaction 2: Pb(NO₃)₂(aq) + Ag(s) → no reaction.
Chemical reaction 3: Cu(NO₃)₂(aq)) + Ni(s) → Ni(NO₃)₂(aq) + Cu(s).
From chemical reactions 1 and 3, we can conclude that nickel is more reactive than lead (Pb) and copper (Cu), because lead is more reactive than silver (Ag), chemical reaction 2, nickel is also more reactive than silver.
In chemical reaction 2, no reaction occurs because silver is less reactive than lead. Lead is higher in activity series of metals and can not be reduced.
Nickel is higher in activity series of metals than lead, copper and silver.
The activity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.
B.gas would has the most kinetic enegry because its particles move freely
Answer:
The solution's new volume is 1.68 L
Explanation:
Dilution is the procedure to prepare a less concentrated solution from a more concentrated one, and simply consists of adding more solvent. So, in a dilution the amount of solute does not vary, but the volume of the solvent varies.
In summary, a dilution is a lower concentration solution than the original.
The way to do the calculations in a dilution is through the expression:
Ci*Vi=Cf*Vf
where C and V are concentration and volume, respectively; and the i and f subscripts indicate initial and final respectively.
In this case, being:
- Ci= 7 M
- Vi= 0.60 L
- Cf= 2.5 M
- Vf=?
Replacing:
7 M*0.60 L= 2.5 M* Vf
Solving:
Vf= 1.68 L
<u><em>The solution's new volume is 1.68 L</em></u>
1 mole ----------- 22.4 L ( at STP )
3.75 moles ----- ?
3.75 x 22.4 / 1 => 84.0 L
The third answer is the one you want. You have to have an adjustable density. All other things being equal, if the tanks you use for holding just water when filled with water will let the sub sink, because the sub is made of a dense metal like iron or steel.
If on the other hand you fill these tanks with air, the net density will be below one and the sub will rise.
