Explanation:
The given reaction is redox reaction but not combustion reaction.
Redox reaction : It is a chemical reaction in which oxidation and reduction occurs simultaneously.Oxidation is gaining of electrons and reduction is loosing of electrons.
oxidation
reduction
Potassium when reacts with water ,gives potassium ion in aqueous medium and combines with hydroxide ion present in water to form potassium hydroxide where as ions of water by gaining electrons (from potassium in water) gives hydrogen gas.
Hence , yes it is a redox reaction
Combustion reaction are the chemical reaction in which one reactant react with oxygen molecule to give heat and light.
Here in given reaction no oxygen molecule is appearing on reactant side.
Hence not a combustion reaction.
Answer:
We need 92.3 grams of sodium azide
Explanation:
Step 1: Data given
Mass of nitrogen gas = 59.6 grams
Molar mass of nitrogen gas = 28.0 g/mol
Molar mass of sodium azide = 65.0 g/mol
Step 2: The balanced equation
2NaN3 → 2Na + 3N2
Step 3: Calculate moles nitrogen gas
Moles N2 = mass N2 / molar mass N2
Moles N2 = 59.6 grams/ 28.0 g/mol
Moles N2 = 2.13 moles
Step 4: Calculate moles NaN3
for 2 moles NaN3 we'll have 2 moles Na and 3 moles N2
For 2.13 moles N2 we need 2/3* 2.13 = 1.42 moles NaN3
Step 5: Calculate mass NaN3
Mass NaN3 = Moles NaN3 * molar mass NaN3
Mass NaN3 = 1.42 moles * 65.0 g/mol
Mass NaN3 = 92.3 grams
We need 92.3 grams of sodium azide
Answer : The correct option is, D
Explanation :
Saturated solution : It is a chemical solution which contain the maximum amount of solute dissolved in the solvent. In saturated solution, the additional amount of solute will not dissolve in the solvent.
When a student has a solution of sodium nitrate then we can check their saturation point by adding additional amount of sodium nitrate. When we add more amount of sodium nitrate in the solution, then all of it will settle down to the bottom of the container.
Therefore, the best evidence for saturated solution is, When additional sodium nitrate is added, it all settles to the bottom of the container.
Answer:
Explanation:
To determine whether a covalent compound contains polar bonds you must deal with dipole moments and symmetry.
If a molecule has dipole moments and the charge is not symmetrically distributed then the covalent ompound is polar.
This is the analysis for the given compounds.
- First of all, AlCl₃ is an ionic compound, because the difference of electronegativities between Al (a metal) and Cl (a nonmetal) atoms is large enough to gender the formation of ions.
- CO₂: since C and O are two nonmetals, with different electronegativities, each C=O bond is polar. Nevertheless, it is a planar molecule (its geometry is O = C = 0) , so the molecule is completely symmetric, and the dipole moments of each C=O pair are cancelled. So, this is not a polar molecule.
- The structure of OCl₂ is similar to that of water (H₂O). So, it is not planar but bended. The bent geometry is due to the lone pairs on the oxygen. Also, due to steric repulsion between the relatively large chlorine atoms the bond angle is a bit larger than the normal angle. While for the H₂O molecules the bond angle is about 104.45°, it is about 110.9° for OCl₂. Then, being it bended, the dipole moment do not cancel and the molecule is polar.