Q1)
the reaction that takes place is
lead nitrate reacting with potassium iodide to form lead iodide and potassium nitrate
balanced chemical equation for the reaction is as follows
Pb(NO₃)₂ + 2KI ----> PbI₂ + 2KNO₃
Q2)
mass of lead nitrate present - 0.600 g
number of moles = mass present / molar mass
number of moles - 0.600 g / 331.2 g/mol = 0.00181 mol
Q3)
mass of potassium iodide present - 0.850 g
number of moles = mass present / molar mass
number of moles of potassium iodide = 0.850 g / 166 g/mol = 0.00512 mol
Q4)
we have to calculate the number of moles of PbI₂ formed based on the number of moles of Pb(NO₃)₂ present assuming the whole amount of Pb(NO₃)₂ was used up
stoichiometry of Pb(NO₃)₂ to PbI₂ is 1:1
number of Pb(NO₃)₂ moles reacted - 0.00181 mol
therefore number of PbI₂ moles formed - 0.00181 mol
Q5)
next we have to calculate the number of moles of PbI₂ formed based on the amount of KI moles present , assuming all the moles of KI were used up in the reaction
stoichiometry of KI to PbI₂ is 2:1
number of moles of KI reacted - 0.00512 mol
then number of moles of PbI₂ formed - 0.00512 x 2 = 0.0102 mol
0.0102 mol of PbI₂ is formed
Q6)
limting reactant is the reactant that is fully consumed during the reaction. the amount of product formed depends on the amount of limiting reactant present
if lead nitrate is the limiting reactant
if 1 mol of Pb(NO₃)₂ reacts with 2 mol of KI
then 0.00181 mol of Pb(NO₃)₂ reacts with - 2 x 0.00181 mol of KI = 0.00362 mol
but 0.00512 mol of KI is present and only 0.00362 mol are required
therefore KI is in excess and Pb(NO₃)₂ is the limiting reactant
Pb(NO₃)₂ is the limiting reactant
Q7)
then the amount of PbI₂ formed depends on amount of Pb(NO₃)₂ present
therefore number of moles of PbI₂ formed is based on number of Pb(NO₃)₂ moles present
as calculated in Question number 4 - Q4
number of PbI₂ moles formed - 0.00181 mol
mass of PbI₂ formed - 461 g/mol x 0.00181 mol = 0.834 g
mass of PbI₂ formed - 0.834 g
Q8)
actual yield obtained is not always equal to the theoretical yield . therefore we have to find the percent yield. This tells us the percentage of the theoretical yield that is actually obtained after the experiment
percent yield = actual yield / theoretical yield x 100 %
percent yield = 0.475 g / 0.834 g x 100 % = 57.0 %
percent yield of lead iodide is 57.0 %
Answer: Option (c) is the correct answer.
Explanation:
Water cycle is a process in which water circulates from point to another into the atmosphere. This means that water in the form of rain falls on the ground and then through the process of evaporation it reaches back to the atmosphere and clouds.
Energy from the Sun is highly responsible for carrying out the process of water cycle. This is because when water falls on from clouds it seeps through rivers, mountains, lakes etc into the oceans and then heat energy from the sun evaporates this water and it rises to make clouds and help in rainfall and snow.
Therefore, we can conclude that energy from the Sun is the most responsible force driving the water cycle.
Answer:
The correct option is;
Waves that move through the Earth
Explanation:
In attempting to unravel the nature and arrangements of the rocks beneath the Earths surface, Geologist apply numerous methodologies including seismological field survey and analysis whereby the time of travel of natural (due to events such as earthquakes) or man made (during geological exploration) seismic wave are analysed to image the nature, composition and dynamism of the Earth's interior to find out the presence of geological faults or liquid layers as well as to predict the possible occurrence of future events within the Earth's crust in detail.
Answer: D) All of the above
Explanation:
The sources of errors in the kinetic experiment are depends upon the tools, due to some personal errors and also due to some methodological problem. As, experimental error during kinetic study is due to the difficulty to characterize the experimental errors depend on reaction conditions. The behavior of the experimental errors are depend on specific feature of the experiment systems.