Answer:
11.7 mL
Explanation:
Density of a substance is given by the mass of the substance divided by the volume of the substance .
Hence , d = m / V
V = volume
m = mass ,
d = density ,
From the question ,
The density of the metal = 10.5 g/cm³
The mass of the metal = 5.25 g
Hence , the volume can be calculated from the above formula , i.e. ,
d = m / V
V = m / d
V = 5.25 g / 10.5 g/cm³
V = 0.5 cm³
Since , The unit 1 mL = 1 cm³
V = 0.5 mL
The vessel has 11.2 mL of water ,
The new volume becomes ,
11.2 mL + 0.5 mL = 11.7 mL
The balanced equation for the reaction is as follows;
Li₂O + H₂O ---> 2LiOH
Stoichiometry of Li₂O to H₂O is 1:1
Mass of Li₂O reacted - 18.9 g
Number of Li₂O moles reacted - 18.9 g / 30 g/mol = 0.63 mol
An equivalent amount of moles of water have reacted - 0.63 mol
mass of water required - 0.63 mol x 18 g/mol = 11.34 g
A mass of 11.34 g of water is required
Answer:
C. chromium is a metal that is less reactive than sodium.
Explanation:
Hello.
Given the options:
A. chromium is a nonmetal and therefore a good conductor of heat and electricity
.
B. chromium is a metal that is more reactive than potassium
.
C. chromium is a metal that is less reactive than sodium
.
D. chromium is a noble gas that is not reactive.
In this case, since chromium is in period 4 group VIB we infer it is a transition metal which slightly reacts with acids and poorly reacts with oxygen and other oxidizing substances. Thus, in comparison with both sodium and potassium which are highly reactive even with water as they get on fire, we can say that it is less reactive than both potassium and sodium, therefore, answer is: C. chromium is a metal that is less reactive than sodium.
Best regards.
