Which drug presents the greatest challenges to forensic science

HELP PLEASE!!! I AM BEING TIMED!<br> I WILL GIVE YOU BRAINLIEST!!

r-ruslan [8.4K]

Answer:

Explanation:

I HOPE IT HELPS :)

3 0

3 years ago

over a 12.3 minuete period 5.13 E-3 moles of F2 gas effuses from a contaier. How many moles of CH4 gas could effuse from from th

Aleonysh [2.5K]

Answer : The moles of methane gas could be, $7.90\times 10^{-3}mol$

Solution :

According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.

$R\propto \sqrt{\frac{1}{M}}$

or,

$(\frac{R_1}{R_2})=\sqrt{\frac{M_2}{M_1}}$

$[\frac{(\frac{n_1}{t_1})}{(\frac{n_2}{t_2})}]=\sqrt{\frac{M_2}{M_1}}$

where,

$R_1$ = rate of effusion of fluorine gas

$R_2$ = rate of effusion of methane gas

$n_1$ = moles of fluorine gas = $5.13\times 10^{-3}mol$

$n_2$ = moles of methane gas = ?

$t_1=t_2$ = time = 12.3 min (as per question)

$M_1$ = molar mass of fluorine gas = 38 g/mole

$M_2$ = molar mass of methane gas = 16 g/mole

Now put all the given values in the above formula 1, we get:

$[\frac{(\frac{5.13\times 10^{-3}mol}{12.3min})}{(\frac{n_2}{12.3min})}]=\sqrt{\frac{16g/mole}{38g/mole}}$

$n_2=7.90\times 10^{-3}mol$

Therefore, the moles of methane gas could be, $7.90\times 10^{-3}mol$

8 0

3 years ago

A solution is made by adding 360 g of table salt into 1 L of water. The solubility of the salt is 36 g/100 mL water. Which term

Oksanka [162]

To express the given concentration of the solution to the same unit as the solubility of the salt, use dimensional analysis.
(360 g/ 1 L ) x (1 L / 10 (100 mL)) = 36 g / 100 mL
This value is equal to the value of the solubility of the salt which means that the solution is SATURATED.

7 0

4 years ago

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a muscle fiber contracts when myosin filaments pull actin filaments closer together and thus shorten sarcomeres within a fiber.

kakasveta [241]

Answer:According to the sliding filament theory, a muscle fiber contracts when myosin filaments pull actin filaments closer together and thus shorten sarcomeres within a fiber.

Explanation:

No need for an explanation if i just answered it

7 0

3 years ago

Based on the reactivities of the elements involved, which reaction will form products that are more stable than the reactants?

LUCKY_DIMON [66]

Answer: The correct option is B.

Explanation: All the given reactions are a type of single displacement reactions.

Single displacement reactions are defined as the reactions in which a more reactive metal displaces a less reactive metal in a chemical reaction.

General equation for these reactions is:

$AB+C\rightarrow CB+A$

For the given reactions, we will use the reactivity series. The metal which lies above in the reactivity series will easily displace the metal which lies below in the reactivity series.

Option A: For this reaction, zinc lies below aluminium in the reactivity series. Hence, zinc will not be able to displace aluminium in the chemical reaction.

Option B: For this reaction, Sodium is more reactive than calcium as it lies above in the reactivity series. Hence, sodium will easily displace calcium in the given chemical reaction.

Reaction follows:

$CaBr_2+2Na\rightarrow 2NaBr+Ca$

Option C: For this reaction, hydrogen lies below magnesium in the reactivity series. Hence, hydrogen will not be able to displace magnesium in the chemical reaction.

Option D: For this reaction, Calcium lies below barium in the reactivity series. Hence, calcium will not be able to displace barium in the chemical reaction.

Option E: For this reaction, barium lies below lithium in the reactivity series. Hence, barium will not be able to displace lithium in the chemical reaction.

Reactivity series is attached below.

3 0

4 years ago

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