Calculate the density of an object that has a mass of 43 g and a volume of 56.0 ml.

The half-life of na-24 is 15 hours . when there are 1000 atoms of na-24 in a sample , a scientist starts a stopwatch . the scien

marin [14]

125 Each half life it divides by 2 the amount
1000/2=500
500/2=250
250/2=125

8 0

3 years ago

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A sample of xenon gas occupies a volume of 6.80 L at 52.0°C and 1.05 atm. If it is desired to increase the volume of the gas sam

Pavlova-9 [17]

Answer:

207.03°C

Explanation:

The following data were obtained from the question:

V1 (initial volume) = 6.80 L

T1 (initial temperature) = 52.0°C = 52 + 273 = 325K

P1 (initial pressure) = 1.05 atm

V2 (final volume) = 7.87 L

P2 (final pressure) = 1.34 atm

T2(final temperature) =?

Using the general gas equation P1V1/T1 = P2V2/T2, the final temperature of the gas sample can be obtained as follow:

P1V1/T1 = P2V2/T2

1.05 x 6.8/325 = 1.34 x 7.87/T2

Cross multiply to express in linear form as shown below:

1.05 x 6.8 x T2 = 325 x 1.34 x 7.87

Divide both side by 1.05 x 6.8

T2 = (325 x 1.34 x 7.87) /(1.05 x 6.8)

T2 = 480.03K

Now, let us convert 480.03K to a number in celsius scale. This is illustrated below:

°C = K - 273

°C = 480.03 - 273

°C = 207.03°C

Therefore, the final temperature of the gas will be 207.03°C

5 0

3 years ago

Which unit is used for measuring atomic mass? A. atomic mole B. grams/mole C. grams D. atomic mass unit E. atomic mass weight

mihalych1998 [28]

The atomic mass is defined as the mass an atom of an element. The atomic mass in approximation is equal to the sum of number of neutrons and protons in the nucleus of an atom (mass number). The units which are used for measuring the atomic mass is atomic mass unit, $u$ .

Thus, the correct option is option E that is atomic mass unit is used for measuring atomic mass.

7 0

3 years ago

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Determine the volume in mL of 0.37 M HClO4(aq) needed to reach the half-equivalence (stoichiometric) point in the titration of 2

Dimas [21]

Answer:

14.3mL you require to reach the half-equivalence point

Explanation:

A strong acid as HClO₄ reacts with a weak base as CH₃CH₂NH₂, thus:

CH₃CH₂NH₂ + HClO₄ → CH₃CH₂NH₃⁺ + ClO₄⁻

As the reaction is 1:1, to reach the equivalence point you require to add the moles of HClO₄ equal to moles CH₃CH₂NH₂ you add originally. Also, half-equivalence point requires to add half-moles of CH₃CH₂NH₂ you add originally.

Initial moles of CH₃CH₂NH₂ are:

20.8mL = 0.0208L × (0.51mol CH₃CH₂NH₂ / 1L) =

0.0106moles CH₃CH₂NH₂

To reach the half-equivalence point you require:

0.0106moles ÷ 2 = 0.005304 moles HClO₄

As concentration of HClO₄ is 0.37M, volume you require to add 0.005304moles is:

0.005304 moles HClO₄ ₓ (1L / 0.37mol) = 0.0143L =

<h3> 14.3mL you require to reach the half-equivalence point</h3>

7 0

3 years ago

PLEASE HELP! GIVING 22 POINTS!

dexar [7]

Differences-
Canis latrans (Coyte) is smaller than Canis lupus (Gray Wolf).
Similarities-
They are both canines and carnivorous.
Hope this helped!
~Wolfe<3

7 0

3 years ago

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