Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
Answer:
50000ppm and 0.855M.
Explanation:
ppm is an unit of chemistry defined as the ratio between mg of solute (NaCl) and Liters of solution. Molarity, M, is the ratio between moles of NaCl and liters
A 5% (w/v) NaCl contains 5g of NaCl in 100mL of solution.
To solve the ppm of this solution we need to find the mg of NaCl and the L of solution:
<em>mg NaCl:</em>
5g * (1000mg / 1g) = 5000mg
<em>L Solution:</em>
100mL * (1L / 1000mL) = 0.100L
ppm:
5000mg / 0.100L = 50000ppm
To find molarity we need to obtain the moles of NaCl in 5g using its molar mass:
5g * (1mol / 58.5g) = 0.0855moles NaCl
Molarity:
0.0855mol NaCl / 0.100L = 0.855M
Answer: Option (A) is the correct answer.
Explanation:
Condensation is defined as the process in which vapors or gaseous phase changes into liquid phase.
Freezing is the process in which liquid phase changes into solid phase.
Evaporation is the process in which liquid phase changes into vapors or gaseous phase.
Melting is the process in which solid phase changes into liquid phase.
Therefore, we can conclude that names for given phase changes A and B is that A is condensation and B is freezing.
A.)49.4974874 moles or 49.5 moles
B.)2.980808730172671e+25 or 3e+25
Answer:
The most important ore of aluminum is<u> Bauxite.</u>
And its chemical formula is 
.
Explanation:
Bauxite is the most important ore of Aluminium from which Aluminium is extracted. Bauxite is a rock and composed of Aluminium bearing mineral.
And its chemical formula is .
It contains Gibbsite, Bohmite and Diaspore along with iron.
It is a soft material with somewhat white to grey to reddish brown in colour.
It has an earthy lustre and low specific gravity.
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