Chromatography is an analytical method of separating components of the mixture. Particularly, this method uses the paper chromatography. The color indicates the type of substance existing. Each substance is designated to one color only. So, if your paper showed more than one color, it mean that there is more than one component in there. Therefore, Kim's specimen contains more than one component because of the red and blue band.
Unit' is the word used to describe how something is measured. When researching a question in science, we collect data, interpret it, and share the results with other scientists. A common measurement system allows us to make direct comparisons instead of having to know things like how much a certain animal weighs.
I believe the answer is 8
The percent composition of each element can be calculated as follows:
% composition = (mass of element / total mass) * 100
The total mass of the quarter is given to be 5.670 grams
Mass of Cu = 5.198 grams
Mass of Ni = 0.472 grams
Substitute in the above equation to get the mass percentage of each element as follows:
% of Cu = (5.198/5.670) * 100 = 91.675%
% of Ni = (0.472/5.670) * 100 = 8.325%
Answer:
4.4 g
Explanation:
Step 1: Write the balanced equation
Cu + 4 HNO₃ ⇒ Cu(NO₃)₂ + 2 NO₂ + 2 H₂O
Step 2: Calculate the moles corresponding to 3.2 L of NO₂ at STP
At standard temperature and pressure, 1 mole of NO₂ occupies 22.4 L.
3.2 L × 1 mol/22.4 L = 0.14 mol
Step 3: Calculate the moles of Cu needed to produce 0.14 moles of NO₂
The molar ratio of Cu to NO₂ is 1:2. The moles of Cu needed are 1/2 × 0.14 mol = 0.070 mol.
Step 4: Calculate the mass corresponding to 0.070 moles of Cu
The molar mass of Cu is 63.55 g/mol.
0.070 mol × 63.55 g/mol = 4.4 g
