if we fix the temperature, we are just left with PV = constant for the gas law. So, in this situation, if the volume is doubled, the pressure must go down by one-half. And vice-versa. The simplest illustration of this would be a cylinder with a plunger on one end: if you push the plunger in so that the volume of the cylinder is halved and the temperature remains constant, then the pressure will double.

7 0

3 years ago

Cobalt-60 is a strong gamma emitter that has a half- life of 5.26 yr. The co balt-60 in a radiotherapy unit must be replaced whe

Alenkasestr [34]

<u>Answer:</u> The sample of Cobalt-60 isotope must be replaced in January 2027

<u>Explanation:</u>

The equation used to calculate rate constant from given half life for first order kinetics:

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

where,

$t_{1/2}$ = half life of the reaction = 5.26 years

Putting values in above equation, we get:

$k=\frac{0.693}{5.26yrs}=0.132yrs^{-1}$

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $0.132yr^{-1}$

t = time taken for decay process = ? yr

$[A_o]$ = initial amount of the sample = 100 grams

[A] = amount left after decay process = (100 - 75) = 25 grams

Putting values in above equation, we get:

$0.132=\frac{2.303}{t}\log\frac{100}{25}\\\\t=10.5yrs$

The original sample was purchased in June 2016

As, June is the 6th month of the year, which means the time period will be $2016+\frac{6}{12}=2016.5$

Adding the time in the original time period, we get:

$2016.5+10.5=2027$

Hence, the sample of Cobalt-60 isotope must be replaced in January 2027

3 0

3 years ago

Draw the structure of two alkenes that would yield 1-methylcyclohexanol when treated with Hg(OAc)2 in water, then NaBH4:Draw the

disa [49]

Answer:

Two possible compounds are shown below- one with an exocyclic double bond and another one with an endocyclic double bond

Explanation:

Reaction of alkene with $Hg(OAc)_{2}$ gives a complex of mercurous ion.

Then water molecule attacks this complex through $S_{N}2$ type reaction at more substituted position.

$NaBH_{4}$ cleaves the resultant C-Hg bond and forms a C-H bond.

Two possible structures of an alkene is possible to yield 1-methylcyclohexanol which are shown below.

3 0

3 years ago

Which describes an impermeable rock where oil and natural gas deposits are found?

love history [14]

Answer:

Explanation:

Groundwater is stored in the open spaces within rocks and within unconsolidated sediments. Rocks and sediments near the surface are under less pressure than those at significant depth and therefore tend to have more open space. For this reason, and because it’s expensive to drill deep wells, most of the groundwater that is accessed by individual users is within the first 100 m of the surface. Some municipal, agricultural, and industrial groundwater users get their water from greater depth, but deeper groundwater tends to be of lower quality than shallow groundwater, so there is a limit as to how deep we can go.

5 0

2 years ago