Answer:
First option
Explanation:
Students 1 and 2 have precise measures yet is is not accurate since they measure around 5.
2.79 mol of MnSiO3
This will be very close but may not be exactly accurate, depending on what your periodic table says.
The number located in the top right corner of the ion is +2
An ion is an atom or group of atoms which possess an electric charge.
The charge on an ion can be obtained by using the following formula:
<h3>Charge = Proton – Electron </h3>
With the above formula, we can obtain the charge of the ion given in the question above as illustrated below:
Proton = 16
Neutron = 17
Electron = 14
<h3>Charge =? </h3>
Charge = Proton – Electron
Charge = 16 – 14
<h3>Charge = +2</h3>
Therefore, the charge on the ion is +2
Learn more: brainly.com/question/3428265
Answer:
[α] = -77.5° / 
Explanation:
Given;
Mass of optically pure substance in the solution = 10 g
Volume of water = 500 mL
Length of the polarimeter, l = 20 cm = 20 × 0.1 dm = 2 dm
measured rotation = - 3.10°
Now,
The specific rotation ( [α] ) is given as:
[α] = 
here,
α is the measured rotation = -3.10°
c is the concentration
or
c = 
or
c = 
or
c = 0.02 g/mL
on substituting the values, we get
[α] = 
or
[α] = -77.5° /
Answer:
The calculated concentration of sodium thiosulphate solution will be less than the actual value.
Explanation:
When IO3^2- solution is added to KI solution, I2 gas is released ,then sulphuric acid is now added to facilitate reduction. In order to prevent the escape of iodine (I2) gas ,the solution must immediately be titrated with thiosulphate.
If the solution is not immediately titrated with thiosulphate, the concentration of iodine available in the system decreases. When this occurs, it will also cause a decrease in the amount of iodine available to react with thiosulphate thus decreasing the concentration of thiosulphate obtained from calculation
