(a) Ka for C6H5NH3+ = Kw/Kb for C6H5NH2 = 10-14/4.27 x 10-10 = 2.342 x 10-5 Henderson-Hasselbalch equation: pH = pKa + log([C6H5NH2]/[C6H5NH3+]) = -log Ka + log([C6H5NH2]/[C6H5NH3+]) 4.20 = -log(2.342 x 10-5) + log(0.50/[C6H5NH3+]) log(0.50/[C6H5NH3+]) = -0.4304 0.50/[C6H5NH3+] = 10-0.4304 = 0.3712 [C6H5NH3+] = 1.347 1.35 M (b) Initial moles of C6H5NH2 = volume x concentration = 1.00 x 0.50 = 0.50 mol Initial moles of C6H5NH3+ = volume x concentration = 1.00 x 1.35 = 1.35 mol C6H5NH3+ + NaOH => C6H5NH2 + H2O + Na+ Moles of NaOH added = mass/molar mass = 4.00/40.00 = 0.100 mol Moles of C6H5NH2 = initial moles of C6H5NH2 + moles of NaOH added = 0.50 + 0.100 = 0.600 mol Moles of C6H5NH3+ = initial moles of C6H5NH3+ - moles of NaOH added = 1.35 - 0.100 = 1.25 mol Henderson-Hasselbalch equation: pH = pKa + log([C6H5NH2]/[C6H5NH3+]) = -log Ka + log(moles of C6H5NH2/moles of C6H5NH3+) since volume = 1.00 L for both = -log(2.342 x 10-5) + log(0.600/1.25) = 4.31 Solution (a) Ka for C6H5NH3+ = Kw/Kb for C6H5NH2 = 10-14/4.27 x 10-10 = 2.342 x 10-5 Henderson-Hasselbalch equation: pH = pKa + log([C6H5NH2]/[C6H5NH3+]) = -log Ka + log([C6H5NH2]/[C6H5NH3+]) 4.20 = -log(2.342 x 10-5) + log(0.50/[C6H5NH3+]) log(0.50/[C6H5NH3+]) = -0.4304 0.50/[C6H5NH3+] = 10-0.4304 = 0.3712 [C6H5NH3+] = 1.347 1.35 M (b) Initial moles of C6H5NH2 = volume x concentration = 1.00 x 0.50 = 0.50 mol Initial moles of C6H5NH3+ = volume x concentration = 1.00 x 1.35 = 1.35 mol C6H5NH3+ + NaOH => C6H5NH2 + H2O + Na+ Moles of NaOH added = mass/molar mass = 4.00/40.00 = 0.100 mol Moles of C6H5NH2 = initial moles of C6H5NH2 + moles of NaOH added = 0.50 + 0.100 = 0.600 mol Moles of C6H5NH3+ = initial moles of C6H5NH3+ - moles of NaOH added = 1.35 - 0.100 = 1.25 mol Henderson-Hasselbalch equation: pH = pKa + log([C6H5NH2]/[C6H5NH3+]) = -log Ka + log(moles of C6H5NH2/moles of C6H5NH3+) since volume = 1.00 L for both = -log(2.342 x 10-5) + log(0.600/1.25) = 4.31.

1. Answer:
The evolutionary history of humans since the most recent common ancestor with chimps is
mainly with development of superior brain with higher intelligence & development of tool
manufacturing skills for hunting. Newly derived traits are such as “enamel on the top of teeth” is
useful to protect when eating hard meat as an evolutionary adaptation that widespread in the
primates including both humans, chimpanzees later. Therefore, newer traits are more widespread
in extant (living) species when compared to the ancestral traits such as postorbital plate which is
separating temporal fossa and orbit for survival function as an older trait (more widespread).
This process of evolution is mainly by anagensis in which traits are more complex over time.
The major traits that distinguish us from chimps and our common ancestors are intelligence,
development of teeth with reduced canines in modern humans and making tools for hunting are
different traits exhibited compared to chimps. The major environmental changes occurred with
temperature and it has increased compared to ancient period. The dietary changes have occurred
with respect to consuming high vegetable rate in humans compared to consumption of animal
meat, which was higher in ancient chimps & hominids.
The locomotion, tools and language have developed differentially in the modern humans
compared to ancient chimps and hominids as explained below.
Superior intelligence produces superior disease resistance:
Archaic humans used widely controlled Fire 250,000 years ago, in order to produce fire.
Hominins used baked clay, bones and charcoal. They widely used fire for cooking purpose these
by eating food, which enabled them with more evolved nervous system and brain with improved
social and physical activities. Finally intelligence, thinking, sexual habits all these process are
improved.
Homo sapiens possess smaller eye brows compared to the above ancestral species. 2. Modern
humans are taller and more gracile associated with falt face and protruding chin as well. 3. Homo
sapiens possess considerably with more brain size compared H. neanderthalensis on average.
Homo sapiens possess a high forehead, as well as flat face, and flat eye brows comape to Homo
denisovans.
Archaic humans are more superior in intelligence compared to the modern humans and they are
more resistant to virulent archaic infections because these are predominantly involved in genetic
variations to produce meticulous cognitive capabilities in ancient humans. Infants who borned in
the ancient period have better immunity capability to produce resistance against various archaic
infections and mothers inherit their disease resistant genetic alleles to the infants so that the
mortality rates are lesser when compared to the present modern humans. In ancient period, there

2. was no industrialization, sewage and pollution to propagate communicable diseases so that there
was no medium to spread infectious disease. Mothers of archaic origins have efficient cognitive
abilities along with smarter brain to defend disease by choosing appropriate nutritious food
material through various learning skills thereby production of more immune factors via breast
milk (improves much resistance in infants) to feed their infants. These features are associated
with eminent superior intelligence in early Homo sapiens to cause low mortality of rates of
infants and mothers.
Ardipithecus ramidus is 4.4 millions years ago and it has locomotor organs with bipedal
property. It possesses a grasping hallux along with big toe and these features are predominantly
adaptations for locomotion in the trees. Their habitat is near to forest including lakes, swamps
and springs associated woodlands and grasslands. Biological eand ecological adaptations include
a better reproductive ability to sustain their race. They possess archaic features to lead their life
along with predation.
They possess hard skeleton and possess reduced canine teeth. They usually communicated with
Afar language. The brain size is smaller compared to apes and chimps and its size is about 300
and 350 cm3. The sexual dimorphism is mainly can be identified by the presence of upper canine
teeth and males prominently possess larger and sharp upper teeth compared to females.
There are 4 distinctive methods of study of anthropology to unravel human life and human
ancestral history.
1. Cultural approach
2. Biological approach
4. Applied scientific approach
5. Contemporary approach
These approaches to study human life as explained below.
The initial evidence of fire originated form the stone hearths and clay control of fire, including
complex hearths, pits and kilns. These three arachiac humans used fire for their living purposes.
1. Homo erectus, 2. Homo sapiens; 3 Neanderthals
Humans may be descended from Neanderthals. The reason is that we have got DNA matching
similarities with Neanderthals as we may belong to these ancestors.
Stone tool culture is the initial and primitive tool choppers to process the collected meat and food
by H. habilis etc.
There is not a close correlation between hominid evolution and climate. There is much impact of
environment on human evolution but not climate change or climate as extinct Hominds and
modern Homo sapiens have evolved according to the genetic changes pertaining to their

3. ancestors. They developed structural adaptations as per their requirement with the habitat as they
are socially communicative, cultural adaptations, behavioral adaptations and hunting adaptations.
These adaptations are crucial to selection pressure by the environment. Habitat on the earth
including land that is suitable for the growth and survival of the Hominid species as they were
perfectly showed adaptations to their environment by producing stronger teeth that made them
sustained to the climate throughout the dry season. Once they are completely adapted, these teeth
went extinct if climate change occurred.
Solution
Answer:
The evolutionary history of humans since the most recent common ancestor with chimps is
mainly with development of superior brain with higher intelligence & development of tool
manufacturing skills for hunting. Newly derived traits are such as “enamel on the top of teeth” is
useful to protect when eating hard meat as an evolutionary adaptation that widespread in the
primates including both humans, chimpanzees later. Therefore, newer traits are more widespread
in extant (living) species when compared to the ancestral traits such as postorbital plate which is
separating temporal fossa and orbit for survival function as an older trait (more widespread).
This process of evolution is mainly by anagensis in which traits are more complex over time.
The major traits that distinguish us from chimps and our common ancestors are intelligence,
development of teeth with reduced canines in modern humans and making tools for hunting are
different traits exhibited compared to chimps. The major environmental changes occurred with
temperature and it has increased compared to ancient period. The dietary changes have occurred
with respect to consuming high vegetable rate in humans compared to consumption of animal
meat, which was higher in ancient chimps & hominids.
The locomotion, tools and language have developed differentially in the modern humans
compared to ancient chimps and hominids as explained below.
Superior intelligence produces superior disease resistance:
Archaic humans used widely controlled Fire 250,000 years ago, in order to produce fire.
Hominins used baked clay, bones and charcoal. They widely used fire for cooking purpose these
by eating food, which enabled them with more evolved nervous system and brain with improved
social and physical activities. Finally intelligence, thinking, sexual habits all these process are
improved.
Homo sapiens possess smaller eye brows compared to the above ancestral species. 2. Modern
humans are taller and more gracile associated with falt face and protruding chin as well. 3. Homo

4. sapiens possess considerably with more brain size compared H. neanderthalensis on average.
Homo sapiens possess a high forehead, as well as flat face, and flat eye brows comape to Homo
denisovans.
Archaic humans are more superior in intelligence compared to the modern humans and they are
more resistant to virulent archaic infections because these are predominantly involved in genetic
variations to produce meticulous cognitive capabilities in ancient humans. Infants who borned in
the ancient period have better immunity capability to produce resistance against various archaic
infections and mothers inherit their disease resistant genetic alleles to the infants so that the
mortality rates are lesser when compared to the present modern humans. In ancient period, there
was no industrialization, sewage and pollution to propagate communicable diseases so that there
was no medium to spread infectious disease. Mothers of archaic origins have efficient cognitive
abilities along with smarter brain to defend disease by choosing appropriate nutritious food
material through various learning skills thereby production of more immune factors via breast
milk (improves much resistance in infants) to feed their infants. These features are associated
with eminent superior intelligence in early Homo sapiens to cause low mortality of rates of
infants and mothers.
Ardipithecus ramidus is 4.4 millions years ago and it has locomotor organs with bipedal
property. It possesses a grasping hallux along with big toe and these features are predominantly
adaptations for locomotion in the trees. Their habitat is near to forest including lakes, swamps
and springs associated woodlands and grasslands. Biological eand ecological adaptations include
a better reproductive ability to sustain their race. They possess archaic features to lead their life
along with predation.
They possess hard skeleton and possess reduced canine teeth. They usually communicated with
Afar language. The brain size is smaller compared to apes and chimps and its size is about 300
and 350 cm3. The sexual dimorphism is mainly can be identified by the presence of upper canine
teeth and males prominently possess larger and sharp upper teeth compared to females.
There are 4 distinctive methods of study of anthropology to unravel human life and human
ancestral history.
1. Cultural approach
2. Biological approach
4. Applied scientific approach
5. Contemporary approach
These approaches to study human life as explained below.

5. The initial evidence of fire originated form the stone hearths and clay control of fire, including
complex hearths, pits and kilns. These three arachiac humans used fire for their living purposes.
1. Homo erectus, 2. Homo sapiens; 3 Neanderthals
Humans may be descended from Neanderthals. The reason is that we have got DNA matching
similarities with Neanderthals as we may belong to these ancestors.
Stone tool culture is the initial and primitive tool choppers to process the collected meat and food
by H. habilis etc.
There is not a close correlation between hominid evolution and climate. There is much impact of
environment on human evolution but not climate change or climate as extinct Hominds and
modern Homo sapiens have evolved according to the genetic changes pertaining to their
ancestors. They developed structural adaptations as per their requirement with the habitat as they
are socially communicative, cultural adaptations, behavioral adaptations and hunting adaptations.
These adaptations are crucial to selection pressure by the environment. Habitat on the earth
including land that is suitable for the growth and survival of the Hominid species as they were
perfectly showed adaptations to their environment by producing stronger teeth that made them
sustained to the climate throughout the dry season. Once they are completely adapted, these teeth
went extinct if climate change occurred.