Answer:- 
molecules.
Solution:- The grams of tetrabromomethane are given and it asks to calculate the number of molecules.
It is a two step unit conversion problem. In the first step, grams are converted to moles on dividing the grams by molar mass.
In second step, the moles are converted to molecules on multiplying by Avogadro number.
Molar mass of 
= 12+4(79.9) = 331.6 g per mol
let's make the set up using dimensional analysis:
= molecules
So, there will be molecules in 250 grams of .
Answer:
CN^- is a strong field ligand
Explanation:
The complex, hexacyanoferrate II is an Fe^2+ specie. Fe^2+ is a d^6 specie. It may exist as high spin (paramagnetic) or low spin (diamagnetic) depending on the ligand. The energy of the d-orbitals become nondegenerate upon approach of a ligand. The extent of separation of the two orbitals and the energy between them is defined as the magnitude of crystal field splitting (∆o).
Ligands that cause a large crystal field splitting such as CN^- are called strong field ligands. They lead to the formation of diamagnetic species. Strong field ligands occur towards the end of the spectrochemical series of ligands.
Hence the complex, Fe(CN)6 4− is diamagnetic because the cyanide ion is a strong field ligand that causes the six d-electrons present to pair up in a low spin arrangement.
Answer: Endothermic reaction
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
As the energy of reactants is 180 kJ and that of products is 300 kJ, the energy of products is greater than that of reactants, which means the energy has been absorbed and reaction is endothermic.
Answer:
(1) 0.10 (2) 17.8 g
Explanation:
Since the reaction ratio is 1:1 what we need is to convert the given masses to moles and you will have the answer:
MW anthracene = 178.23 g/mol
MW maleic anhydride = 98.06 g/mol
a) mass anthracene = 178 mg x 1 g/ 1000 mg = 0.178 g anthracene
Moles anthracene = 0.178 g anthracene/ 178.23 g/mol
= 0.001 mol anthracene
0.001 mol anthracene x 1 mol maleic acid/mol anthracene
= 0.001 mol maleic anhydride
mass maleic anhydride = 0.001 mol x 98.06 g/mol = 0.10 g
b) moles maleic anhydride = 9.8 g/ 98.06 g/mol = 0.099 moles
0.099 moles maleic anhydride x 1 mol anthracene/mol maleic anhydride =
0.099 mol anthracene
g anthracene = 0.10mol x 178 g/mol = 17.8 g
Answer:
Explanation:
Concentration: i is defined as the mole per litre.
mole=0.15
volume=400 ml=0.4 litre
