The purpose is that it shows you all the elements we know and it arranges them in groups that are also the same kind like Chemistry.
Answer:
53.29% of acetic acid is Oxygen
Explanation:
Step 1: Given data
Acetic acid it's molecular formula is HC2H3O2. This means it consists of 3 elements Carbon, Hydrogen and oxygen.
Step 2: the molar masses
The molecular mass of acetic acid is:
4* H = 4* 1.01 g/mole
2* C = 2*12 g/mole
2*O = 2* 16 g/mole
Total molar mass = 4+ 24+32 = 60.052 g/mole
Step 3: Calculate the mass percent
32 g of the 60.052 g is Oxygen
(32/60.052) *100% = 53.29%
53.29% of acetic acid is Oxygen.
To solve this question, we first need to know the mass of one mole of mercury. This can be done by checking the periodic table.
From the periodic table, we can see that:
molar mass of mercury = 200.59 grams/mole.
From the measurements, the chemist found that the participated amount of mercury is 0.02 moles.
We can simply determine the mass of 0.02 moles by doing cross multiplication as follows:
mass of 0.02 moles = (0.02 x 200.59) / 1 = 4.0118 grams
Rounding the answer to 2 significant digits, we get:
mass of 0.02 moles = 4.01 grams
Answer:
Magnesium (Mg)
Explanation:
An element with a lower atomic mass than Calcium that has similar chemical property is the element Magnesium (Mg).
This because, elements in the same group or family on the periodic table has similar chemical properties.
Magnesium belongs to the same group as Calcium, other elements are:
Be Mg Ca Sr Ba Ra
The group is made of the alkaline earth metals. They have two valence electrons in their outer shell.
If my math is right, it should be around 4.33x10^23
To get this you need to find the atomic weight of MgI2, which is around 278. You divide the mass in grams by the atomic mass to find Moles, then you multiply the moles by Avogadros number: 6.022x10^23. Hope I was helpful
