Answer:
If a solution conducts electricity, it is positive evidence that solute dissolved in solvent is electrolyte.
Answer:
Indicators show changes in the pH of a solution
Explanation:
A pH meter is an instrument that measures the hydrogen-ion activity in aqueous solutions, indicating the acidity or alkalinity of the solution expressed as pH .The pH meter measures the difference in electrical potential between a pH electrode and a reference electrode, hence the pH meter is sometimes referred to as a potentiometric pH meter. Potentiometric pH meters measure the voltage between two electrodes and display the result converted into the corresponding pH value. The instrument comprises of a simple electronic amplifier and a pair of electrodes, or alternatively a combination electrode, and some form of display calibrated in pH units. It usually has a glass electrode and a reference electrode, or a combination electrode. The electrodes, or probes, are inserted into the solution to be tested.
Organic indicators are chemical species that change their colour in response to changes in the pH of the solution. This implies that the anionic and protonated forms of the indicator possess different colours. Hence the colour changes in acidic, basic and neutral solutions. The images attached indicate the colour changes in phenolphthalein and methyl orange in acidic and basic media accordingly.
Answer:
B) Iron (c=0.45 J/g°C)
Explanation:
Given that:-
Heat gain by water = Heat lost by metal
Thus,
Where, negative sign signifies heat loss
Or,
For water:
Mass = 120 g
Initial temperature = 21.8 °C
Final temperature = 24.5 °C
Specific heat of water = 4.184 J/g°C
For metal:
Mass = 40.2 g
Initial temperature = 99.3 °C
Final temperature = 24.5 °C
Specific heat of metal = ?
So,
<u>This value corresponds to iron. Thus answer is B.</u>