Phenolphthalein<span> is often used as an indicator in acid–base titrations. For this application, it </span>turns<span> colorless in acidic solutions and </span>pink<span> in basic solutions. </span>Phenolphthalein<span> is slightly soluble in water and usually is dissolved in alcohols for use in experiments.
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Answer:
a) ammonium ion
b) amide ion
Explanation:
The order of decreasing bond angles of the three nitrogen species; ammonium ion, ammonia and amide ion is NH4+ >NH3> NH2-. Next we need to rationalize this order of decreasing bond angles from the valence shell electron pair repulsion (VSEPR) theory perspective.
First we must realize that all three nitrogen species contain a central sp3 hybridized carbon atom. This means that a tetrahedral geometry is ideally expected. Recall that the presence of lone pairs distorts molecular structures from the expected geometry based on VSEPR theory.
The amide ion contains two lone pairs of electrons. Remember that the presence of lone pairs causes greater repulsion than bond pairs on the outermost shell of the central atom. Hence, the amide ion has the least H-N-H bond angle of about 105°.
The ammonia molecule contains one lone pair, the repulsion caused by one lone pair is definitely bless than that caused by two lone pairs of electrons hence the bond angle of the H-N-H bond in ammonia is 107°.
The ammonium ion contains four bond pairs and no lone pair of electrons on the outermost nitrogen atom. Hence we expect a perfect tetrahedron with bond angle of 109°.
Answer:
A one-step mechanism involving a transition state that has a carbon partially bonded to both chlorine and oxygen
Explanation:
The compound CH3Cl is methyl chloride. This is a nucleophilic substitution reaction that proceeds by an SN2 mechanism. The SN2 mechanism is a concerted reaction mechanism. This means that the departure of the leaving group is assisted by the incoming nucleophile. The both species are partially bonded to opposite sides of the carbon atom in the transition state.
Recall that an SN2 reaction is driven by the attraction between the negative charge of the nucleophile (OH^-) and the positive charge of the electrophile (the partial positive charge on the carbon atom bearing the chlorine leaving group).
Explanation:
Given parameters:
Density of silver = 10.5g/cm³
Volume of silver given = 4mL
Unknown:
Mass of silver = ?
Solution:
Density of a substance can be expressed as its mass per unit volume
Density = 
we need to convert our volume to cm³ from mL;
1cm³ = 1mL
So 4mL = 4cm³
input the values in;
Mass = density x volume = 10.5 x 4 = 42g
learn more:
Density brainly.com/question/8441651
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