Compared to pure water, an aqueous solution of calcium chloride has what?

A plane has a cruising speed of 100 miles per hour when there is no wind. At this speed, the plane flew 600 miles with the wind

alina1380 [7]

The solution for this problem is:
Let x = speed of wind

Speed of plane with the wind = x + 100

Speed of plane against the wind = 100 -x

We will be using the formula for distance which is (Rate)(Time), getting the formula for time would be distance/rate Time to travel 600 miles with the wind = Time to travel 400 miles against the wind 600/(x + 100) = 400/(100 - x)

400(x + 100) = 600(100 - x)

400x + 40000 = 60000 - 600x

1000x = 20000

x = 20000/1000

x = 20 mph

8 0

3 years ago

Based on table N of the reference tables what is the number of hours required for 42k (potassium -42) to undergo three half-life

skelet666 [1.2K]

The number of hours required : 37.2 hours

<h3>Further explanation</h3>

Given

⁴²K (potassium -42)

Required

The number of hours

Solution

The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.

Usually, radioactive elements have an unstable atomic nucleus.

Based on Table N(attached), the half-life for ⁴²K is 12.4 hours, which means half of a sample of ⁴²K will decay in 12.4 hours

For three half-life periods :

$\tt 3\times 12.4=37.2~hours$

3 0

3 years ago

150.0 grams of an isotope with a half-life of 36.0 hours is present at time zero. How long will it take

leonid [27]

Given :

Initial mass , a = 150 gm .

Half time ,

$t_{\dfrac{1}{2}}=36 \ hours$ .

Final mass , x = 18.75 gm .

To Find :

The time taken to decay 18.75 gm .

Solution :

We know , time taken is given by :

$t=\dfrac{1}{k}\times ln(\dfrac{a}{a-x})$

Here , k is a constant given by :

$k=\dfrac{0.693}{t_{\dfrac{1}{2}}}\\\\\\k=\dfrac{0.693}{36}$

Putting all given value in above equation :

We get :

$t=\dfrac{36}{0.693}\times ln(\dfrac{150}{150-18.75})\\\\t=6.94\ hours$

Therefore , time taken is 6.94 hours .

Hence , this is the required solution .

5 0

4 years ago

The method used to determine the equivalence point of an acid-base solution is called:

Sveta_85 [38]

Answer is: B) titration.

Equivalence point is the point in which there is stoichiometrically equivalent amounts of acid and base.

Chemist can draw pH curve (graph showing the change in pH of a solution, which is being titrated) for titration and determine equivalence point.

The midpoint of a steep vertical section indicates the equivalence point

8 0

3 years ago

Read 2 more answers

Naturally occurring Indium has two isotopes.

trasher [3.6K]

Answer:

Average Molar mass is 114.8u

Explanation:

» From the formula of average Relative Atomic Mass [ RAM ]

${ \rm{RAM = \sum \frac{(isotopic \: mass \times \%abundance)}{100} }} \\$

» We have two isotopes of Indium,

Indium-113, mass » 112.9u, % » 4.28%
Indium-115, mass » 114.9u, % » 95.72%

${ \tt{RAM = \frac{ \blue{(112.9 \times 4.28)} + { \green{(114.9 \times 95.72)}}}{100} }} \\ \\ { \tt{RAM = \frac{11481.44}{100} }} \\ \\ { \underline{ \underline{ \tt{ \: RAM = 114.8\: }}}}$

3 0

2 years ago