Answer:
HF(aq)+NaOH(aq)→NaF(aq)+H2O(l)
Explanation:
Complete question
Dissolved hydrofluoric acid reacts with dissolved sodium hydroxide to form water and aqueous sodium fluoride. What is the net ionic equation
Equilibrium equation between the undissociated acid and the dissociated ions
HF(aq)⇌H+(aq)+F−(aq)
Sodium hydroxide will dissociate aqueous solution to produce sodium cations, Na+, and hydroxide anions, OH−
NaOH(aq)→Na+(aq)+OH−(aq)
Hydroxide anions and the hydrogen cations will neutralize each other to produce water.
H+(aq)+OH−(aq)→H2O(l)
On combining both the equation, we get –
HF(aq)+Na+(aq)+OH−(aq)→Na+(aq)+F−(aq)+H2O(l)
The Final equation is
HF(aq)+NaOH(aq)→NaF(aq)+H2O(l)
Answer:
The top layer is the Aqueous layer, and the benzoic acid is contained in the non-aqueous layer/oil phase.
Explanation:
A separating funnel is a very important piece of laboratory glassware that is used to separate the components of liquid-liquid mixtures which are immiscible. This technique is used in the extraction of the components of mixtures.
The liquids separate into two phases. The separation is based on the differences in the liquids' densities, where the denser liquid settles below and the lower density liquid stays afloat. Liquids used for this kind of separation are usually different liquids, one is the aqueous layer and the other, a non-aqueous layer.
Partition coefficient or distribution coefficient is defined as the ratio of the concentrations of a compound in two immiscible solvents at equilibrium.
Organic solvents (except halogenated organic compounds) with densities greater than that of water i.e 1g/mL ( usually called the oil phase) settle at the bottom of the aqueous phase.
Benzoic acid. will settle at the bottom layer ( i.e the lower phase).
Whether water is frozen, in a gaseous state, or is a liquid, it is still H2O. So the chemical composition does stay the same.
The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
Oxidation state of Pb in PbO2 is +4.
Oxidation state of Pb in PbCl2 is +2.
Oxidation state of Pb in Pb2O is +1.
Oxidation state of Pb in Pb4O3 is +6/4.
Hence option A. PbO2 is correct.
Hope this helps, have a nice day!
