M=D*V
D=620 g/cm³
V=75 cm³
m= 620 g/cm³ * 75 cm³=46500 g
m=46500g
The balanced chemical equation that represents the reaction is as follows:
<span>SrBr2(aq) + 2AgNO3(aq) → Sr(NO3)2(aq) + 2AgBr(s)
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From the periodic table:
mass of silver = 108 grams
mass of bromine = 80 grams
molar mass of silver bromide = 108 + 80 = 188 grams
number of moles = mass / molar mass
number of moles of produced precipitate = 3.491/188 = 0.018 moles
From the balanced equation:
1 mole of strontium bromide produces 2 moles of silver bromide. Therefore, to calculate the number of moles of <span>strontium bromide that produces 0.018 moles of silver bromide, you will just do a cross multiplication as follows:
amount of </span><span>strontium bromide = (0.018x1) / 2 = 9.28 x 10^-3 moles</span>
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We know both the elements involved in bonding are non-metals and the primary type of bonds involved in non-metals are covalent bonds. Covalent bonds are formed when two atoms share one or more electrons; thus we know that whatever the number of electrons shared, it has to be equal for both. We can eliminate choices A and B.
Next, we understand that it is easier for one atom to be shared among the two, rather than the 7. First, because Hydrogen needs only 1 electron to be stable and would require energy to compensate the remaining 6. Second, electrons are attracted towards the nucleus so it is inefficient to try and share 7 electrons when 1 provides the same amount of stability to Fluorine.
Therefore, the answer is C.
Answer:
4
Explanation:
Relationship between wavenumber and Rydberg constant (R) is as follows:
Here, Z is atomic number.
R=109677 cm^-1
Wavenumber is related with wavelength as follows:
wavenumber = 1/wavelength
wavelength = 253.4 nm
Z fro Be = 4
Therefore, the principal quantum number corresponding to the given emission is 4.
Answer:
Sort the lab chemicals in alphabetical order for quick access.
Become familiar with the chemicals to be used, including exposure or spill hazards.
Locate the spill kits and understand how they are used.
Explanation:
There are many chemicals in a laboratory hence they should be sorted out and arranged in alphabetical order so that theory can easily be identified and located whenever they are required.
The properties of each chemical should be known especially hazards connected to exposure or spill of the chemicals.
The students should also familiarize themselves with the contents of spill kits and how they are used.
