Answer:
True statment
2) Styrofoam would make a good calorimeter
3) Insulating material would make a good calorimeter
Explanation:
The calorimeter is one which is insulated that is which will not absorb or let the heat to escape from it. the calorimeter is used to measure the heat change during a process so if it will allow to exchange heat with surrounding it will deviate the readings or observence.
Copper is a good conductor of heat so we cannot use it make a calorimeter.
Hence
1) Copper would make a good calorimeter : False
2) Styrofoam would make a good calorimeter: True
Styrofoam is a bad conductor or insulator so it can be and it is used for calorimeter.
3) Insulating material would make a good calorimeter
: True
4) A good calorimeter should easily absorb heat : false
Explanation:
Take shelter in a hard wall building
Close doors and windows cut off ventilation
Combustion means the burning of something. So in the given question, you could say, “In this question, combustion means the burning of methane”.
Electronegativity of boron is the highest in the group and it will form covalent bonds in all his combinations.
The rest of the group will form bonds with intermediate nature between covalent and ions bods in their respective compounds, with thallium (Tl) behaving most close to a metal.
Moreover boron have a very high melting points (around 2200 °C) while in the boron cristal the chemical bonds are directed in space, similar with carbon suggesting his nature as a non-metal.
Other elements form the group Al, Ga, In, Tl have lower melting points 660, 30, 157 and 304 °C, respectively. Also in the elemental state, they have metallic characteristics: metalic luster, ductility, high electrical and thermal conductivity.
Answer:
9.1 seconds
Explanation:
Given that for a second order reaction
1/[A]t = kt + 1/[A]o
Where [A]t= concentration at time = t= 0.340M
[A]o= initial concentration = 0.820M
k= rate constant for the reaction=0.190m-1s-1
t= time taken for the reaction (the unknown)
Hence;
(0.340)^-1 = 0.190×t + (0.820)^-1
t= (0.340)^-1 - (0.820)^-1/0.190
t= 9.1 seconds
Hence the time taken for the concentration to decrease from 0.840M to 0.340M is 9.1 seconds.
