Answer:
Ammonium chloride, iron ,Sulphur and salt mixed together... they can be separated in the following methods.
1. Ammonium chloride is separated by sublimination... NC4CI is sublimable. Heat the mixture in a china dish and collect the funds of NC4CI (sublimable substance)
2. Bring a magnet close to the remaining mixture. Iron is magnetic substance and thus, it will be attracted towards the magnet. Iron is separated.
3. Sulphur is insoluble in water and salt is soluble. Add water to the remaining mixture and then wait for sedimentation. Separate the sulphur by decantation.
4. Heat the filtered salt solution to obtain salt.
Answer: Marcia made a more concentrated salt solution.
Explanation:
Marcia used 1 kg of salt, which the exercise tells us is 2.2 lb.
She dissolved it in 3L of water, so we have to find out how much that is in pints. We do that using cross multiplication.
If 1L equals 2.11 pints, then
xpints / 3L = 2.11pints / 1L, so
xpints = (3L . 2.11pints) / 1L = 6.33 pints
Now we know she dissolved 2.2lb in 6.33 pints of water. We use cross multiplication again to find out how much salt she would have in 10 pints, so we can know how concentrated it is compared to Bobby's solution, which is 10 pints.
xlb / 10pints = 2.2lb / 6.33pints
xlb = (10pints . 2.2lb) / 6.33pints = 3.47lb
So Marcia has a concentration of 3.47lb per 10 pints, whereas Bobby only has 3lb per 10 pints.
The required mass of calcium bromide is 35.98 grams.
<h3>What is molarity?</h3>
Molarity is any solution is define as the number of moles of solute present in per liter of solution as;
M = n/V, where
- M = molarity = 4M
- V = volume = 45mL = 0.045L
Moles will be calculated by using the above equation as:
n = (4)(0.045) = 0.18 mole
Relation between the mass and moles of any substance will be represented as:
n = W/M, where
- W = given mass
- M = molar mass
Mass of CaBr₂ = (0.18mol)(199.89g/mol) = 35.98g
Hence required mass of CaBr₂ is 35.98 grams.
To know more about molarity, visit the below link:
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An igneous rock is defined by how the rock is formed; igneous rocks are formed by the solidification of molten rock materials. Examples of igneous rocks include Diorite, Gabbro, Granite, Pegmatite.
Here we have to get the symbol of the selenium ion having two extra electrons.
The symbol of the selenium ion with two extra electrons is 
.
The number of electrons present in selenium is 34. The electronic configuration of selenium (Se) is 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁴.
Now we can see that there are 4 electrons in p-orbital. The p-orbital can take maximum 6 electrons thus there is two vacant space in 4p orbital for selenium. If we add two electrons then the total number of electrons will be 36. The electronic configuration can be written as:
[Se²⁻] = 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶.
The two negative charge on selenium makes it an anion as one electron always posses one unit negative charge. Thus for the incorporation of the two electrons there will be accumulation of two negative charge on the selenium atom and it will be expressed as Se²⁻.
