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3 years ago

12

Pls answer I am giving lots of points and need all the work shown. Determine the kb for chloroform when 0.793 moles of solute in

0.758 kg changes the boiling point by 3.80 °C.

1 answer:

navik [9.2K]3 years ago

8 0

Answer:0.87

Explanation:

You might be interested in

The answer to (3.540)x(0.0065)x(401) should have ____.

miv72 [106K]

B. Two significant figures

Your final answer can only have as many significant figures as the number that has the least amount of significant figures in it, which is (0.0065)

3 0

3 years ago

29. A gas has a volume of 1.75 L at -23°C and 150.0 kPa.

arsen [322]

The answer for the following mention bellow.

<u><em>Therefore the final temperature of the gas is 260 k</em></u>

Explanation:

Given:

Initial pressure ( $P_{1}$ ) = 150.0 kPa

Final pressure ( $P_{2}$ ) = 210.0 kPa

Initial volume ( $V_{1}$ ) = 1.75 L

Final volume ( $V_{2}$ ) = 1.30 L

Initial temperature ( $T_{1}$ ) = -23°C = 250 k

To find:

Final temperature ( $T_{2}$ )

We know;

According to the ideal gas equation;

P × V = n × R ×T

where;

P represents the pressure of the gas

V represents the volume of the gas

n represents the no of moles of the gas

R represents the universal gas constant

T represents the temperature of the gas

We know;

$\frac{P*V}{T}$ = constant

$\frac{P_{1} }{P_{2} }$ × $\frac{V_{1} }{V_{2} }$ = $\frac{T_{1} }{T_{2} }$

Where;

( $P_{1}$ ) represents the initial pressure of the gas

( $P_{2}$ ) represents the final pressure of the gas

( $V_{1}$ ) represents the initial volume of the gas

( $V_{2}$ ) represents the final volume of the gas

( $T_{1}$ ) represents the initial temperature of the gas

( $T_{2}$ ) represents the final temperature of the gas

So;

$\frac{150 * 1.75}{210 * 1.30}$ = $\frac{260}{T_{2} }$

( $T_{2}$ ) =260 k

<u><em>Therefore the final temperature of the gas is 260 k</em></u>

<u><em></em></u>

3 0

3 years ago

A fossil was analyzed and determined to have a carbon-14 level that is 70 % that of living organisms. The half-life of C-14 is 5

Citrus2011 [14]

Answer: 2948

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{5730}=1.21\times 10^{-4}years^{-1}$

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $1.21\times 10^{-4}years^{-1}$

t = age of sample = ?

a = let initial amount of the reactant = 100

a - x = amount left after decay process = $\frac{70}{100}\times 100=70$

$t=\frac{2.303}{1.21\times 10^{-4}}\log\frac{100}{70}$

$t=2948years$

Thus the fossil is 2948 years old.

5 0

3 years ago

A marble rolls off horizontally from the edge of table top 1.50 m above the floor. it strikes the floor 2.0 m from the base of t

GrogVix [38]

a. t=0.553 s

b. vox(horizontal speed) = 3.62 m/s

<h3>Further explanation</h3>

Given

h = 1.5 m

x = 2 m

Required

a. time

b. vo=initial speed

Solution

Free fall motion

a. h = 1/2 gt²(vertical motion=h=voyt+1/2gt²⇒voy = 0)

$\tt t=\sqrt{\dfrac{2h}{g} }$

t = √2h/g

t = √2.1.5/9.8

t=0.553 s

b. x=vox.t(horizontal motion)

$\tt x=v_{ox}\times t$

vox=x/t

vox=2/0.553

vox=3.62 m/s

3 0

2 years ago

Which of the following statements are true of acids and bases?

gtnhenbr [62]

A. Acids increase the number of OH- ions in a solution. FALSE
B. Bases increase the number of OH- ions in a solution. TRUE
C. Acids increase the number of H+ ions in a solution. TRUE
D. Bases increase the number of H+ ions in a solution. FALSE

8 0

3 years ago