Answer:
independent variable -- different batteries
dependent variable -- the time that clock stop
Explanation:
In an experiment or a research study, there are two type of variables that can affect the result of the experiment or the conclusion. They are independent variable and the dependent variable.
An independent variable may be defined as that variable in an experiment which can be changed or can be controlled in the scientific experiment in order to test the effect on the dependent variable. It cannot be changed by other variables.
On the other hand, dependent variable are those are those which can be altered or change that can affect the experiment.
In the context, Emily uses the different types of the batteries as an independent variable and the time where the clock stopped in the dependent variable in her research.
Answer:
Making oxygen
Oxygen can be made from hydrogen peroxide, which decomposes slowly to form water and oxygen:
hydrogen peroxide → water + oxygen
2H2O2(aq) → 2H2O(l) + O2(g)
The rate of reaction can be increased using a catalyst, manganese(IV) oxide. When manganese(IV) oxide is added to hydrogen peroxide, bubbles of oxygen are given off.
Apparatus arranged to measure the volume of gas in a reaction. Reaction mixture is in a flask and gas travels out through a pipe in the top and down into a trough of water. It then bubbles up through a beehive shelf into an upturned glass jar filled with water. The gas collects at the top of the jar, forcing water out into the trough below.
To make oxygen in the laboratory, hydrogen peroxide is poured into a conical flask containing some manganese(IV) oxide. The gas produced is collected in an upside-down gas jar filled with water. As the oxygen collects in the top of the gas jar, it pushes the water out.
Instead of the gas jar and water bath, a gas syringe could be used to collect the oxygen.
Answer:
The boiling point is 308.27 K (35.27°C)
Explanation:
The chemical reaction for the boiling of titanium tetrachloride is shown below:
Ti
⇒ Ti
ΔH°
(Ti) = -804.2 kJ/mol
ΔH° (Ti) = -763.2 kJ/mol
Therefore,
ΔH° = ΔH° (Ti) - ΔH° (Ti) = -763.2 - (-804.2) = 41 kJ/mol = 41000 J/mol
Similarly,
s°(Ti) = 221.9 J/(mol*K)
s°(Ti) = 354.9 J/(mol*K)
Therefore,
s° = s° (Ti) - s°(Ti) = 354.9 - 221.9 = 133 J/(mol*K)
Thus, T = ΔH° /s° = [41000 J/mol]/[133 J/(mol*K)] = 308. 27 K or 35.27°C
Therefore, the boiling point of titanium tetrachloride is 308.27 K or 35.27°C.
Answer:
with the help of the juice contained in it
