Answer: A) Storing experimental samples
Explanation:
It is a common piece of laboratory glassware that can be made of glass or plastic and is opened at the top and closed at the bottom.
It cannot be used for measurements because there is no graduation indicating the volume.
Althought it can contain extra chemicals left over from an experiment, it is not the main proposal of the glassware that is to store samples.
It cannot be used in a microscope and the object for that is a microscope slide.
Answer:
Explanation:
The first one is CrO. The Chromium has the same charge as the oxygen so mol numbers are dropped.
The Second one is CrO2 The two oxygens have a charge of 2(-2) = -4. To balance this, the Chromium must have a charge of +4 Cr(Iv)O2
The third one is can be set up like this
Cr + 3(-2) = 0
Cr - 6 = 0
Cr = 6
Therefore the formula is Cr(vi)O3
The last one is a bit tricky. Follow this carefully. There are 2 Crs and 3Os.
The formula looks like this
2Cr + 3(-2) = 0
2Cr - 6 = 0
2Cr = 6
Cr = 3
The formula is Cr(iii)2 O3
Answer:
CH₂
Explanation:
Given parameters:
Percentage composition:
Carbon = 40.1%
Hydrogen = 6.6%
Unknown:
Empirical formula of the compound = ?
Solution:
The empirical formula of a substance is its simplest formula.
Elements Carbon Hydrogen
Percentage
Composition 40.1 6.6
Molecular mass 12 1
Number of moles 40.1/12 6.6/1
3.342 6.6
Divide through by
the smallest 3.342/3.342 6.6/3.342
1 2
So the empirical formula of the compound is CH₂
The age of the fossil given the present amount of Carbon-14 is given in the equation,
A(t) = A(o)(0.5)^t/h
where A(t) is the current amount, A(o) is the initial amount, t is time and h is the half-life. Substituting the known values to the equation,
A(t) / A(o) = 0.125 = (0.5)^(t/5730)
The value of t from the equation is 17190.
Thus, the age of the fossil is mostly likely to be 17190 years old.
Iodine would have chemical properties most like Fluorine, Chlorine and other elements in group 7
