Ni solution could be used to remove lead from lead (II) nitrate.
Explanation:
The removal of lead from lead nitrate will take place by displacement reaction.
In displacement reaction less reactive element is displaced by more reactive element form it compound.
The reactivity is decided by the placement of metal in the activity series.
A metal which is at higher position in the activity series will be able to displace the metal or element having lower position.
From the options given we will check their position in the activity series in comparison to Pb
Cu is lower in series than Pb hence cannot displace.
Hg is placed lower in the series than Pb hence cannot displace Pb.
Ag is placed lower than Pb in the series hence cannot displace Pb.
Ni is placed above the Pb in activity series hence can displace lead.
<u>Answer:</u>
<em>The option a termed as precipitation reaction is incorrectly labelled.
</em>
<u>Explanation:</u>
The chemical reactions are classified based on the reactants used and products formed in a reaction. They are decomposition reaction, single displacement reaction, double displacement reaction, acid-base neutralisation reaction, precipitation reaction, combustion reaction, redox reaction and organic reaction.
Among these, the given options are labelled as precipitation and combustion reaction. The one which is labelled as combustion reaction is correct because combustion reactions occur in the presence of oxygen only and the products of combustion reaction should include water, oxygen or carbon and heat.
The other option which is labelled as precipitation reaction is incorrect because precipitation reaction occurs when an ionic substance will come out of a solution due to heating it or stirring it making the solubility of the ionic substance in a solution zero such that it will come out as solid and form a layer at the bottom of the solution.
But in this case all the products are in aqueous state, there is absence of any ionic substance in solid state, so the option which is labelled as precipitation reaction is incorrectly labelled.
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
The force exerted on the parked car by the moving car is –30000 N
To solve this question, we'll begin by calculating the deceleration of the moving car. This can be obtained as follow:
Initial velocity (u) = 10 m/s
Final velocity (v) = 0 m/s
Time (t) = 0.5 s
<h3>Deceleration (a) =?</h3>
<h3>a = - 20 m/s</h3>
Finally, we shall determine the force exerted by the moving car on the parked car. This can be obtained as follow:
Mass of moving car (m) = 1500 Kg
Acceleration (a) = - 20 m/s
<h3>Force (F) =.?</h3>
F = ma
F = 1500 × (-20)
<h3>F = -30000 N</h3>
NOTE: The negative sign indicate force is in opposite direction to the parked car.
Therefore, the force exerted on the parked car by the moving car is –30000 N
Learn more: brainly.com/question/15430805
