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
NaOH reacts with CH3COOH in 1:1 molar ratio to produce CH3COONa
NaOH + CH3COOH → CH3COONa + H2O
Mol CH3COOH in 52.0mL of 0.35M solution = 52.0/1000*0.35 = 0.0182 mol CH3COOH
Mol NaOH in 19.0mL of 0.40M solution = 19.0/1000*0.40 = 0.0076 mol NaOH
These will react to produce 0.0076 mol CH3COONa and there will be 0.0182 - 0.0076 = 0.0106 mol CH3COOH remaining in solution unreacted . Total volume of solution = 52.0+19.0 = 71mL or 0.071L
Molarity of CH3COOH = 0.0106/0.071 = 0.1493M
CH3COONa = 0.0076 / 0.071 = 0.1070M
pKa acetic acid = - log Ka = -log 1.8*10^-5 = 4.74.
pH using Henderson - Hasselbalch equation:
pH = pKa + log ([salt]/[acid])
pH = 4.74 + log ( 0.1070/0.1493)
pH = 4.74 + log 0.717
pH = 4.74 + (-0.14)
pH = 4.60.
Answer:
1 . 
2. 
Explanation:
The more stable the ionic compound, the more is it lattice energy.
- The more the charge on the cation and the anion, the greater is the lattice energy.
- The less the size of the cation and the anion, the greater is the lattice energy.
Scandium oxide (
) is an oxide in which 
behaves as cation and 
behaves as anion.
The compounds which has higher lattice energy than scandium oxide are:
1 .
This is because the charge are same on the cation and the anion as in the case of the Scandium oxide but the size of the cation 
is smaller than . Thus, this corresponds to higher lattice energy.
2.
This is because the charge on the cation 
is greater than that of and also the size of the cation is smaller than . Thus, this corresponds to higher lattice energy.
Answer:
The weigth of a 90kg man standing on the moon is <u><em>147.6 N (option C)</em></u>
Explanation:
Weight is called the action exerted by the force of gravity on the body.
The mass (amount of matter that a body contains) of an object will always be the same, regardless of where it is located. Instead, the weight of the object will vary according to the force of gravity acting on it.
The formula that allows you to calculate the weight of any body is:
W = m*g
where:
- W = weight measured in N.
- m = mass measured in kg.
- g = acceleration of gravity measured in m/s². The acceleration of gravity g is the same for all objects that fall due to gravitational attraction, whatever their size or composition. For example, as an approximate value on Earth, g = 9.8 m/s².
In this case, the mass m has a value of 90 kg and the gravity g has a value of 1.64 m/s², which is the value of the acceleration of gravity of the moon. Then:
W=90 kg* 1.64 m/s²
<u><em>W= 147.6 N</em></u>
Finally, <u><em>the weigth of a 90kg man standing on the moon is 147.6 N (option C)</em></u>
Answer:
86,400 seconds in a day.
Explanation:
There are 24 hrs in a day. So there are 2460 mins in a day. ( 1hr=60 mins) So there are 246060 seconds in a day. (1 min = 60 seconds) Therefore 86,400 seconds in a day.
