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2 years ago

Calculate the mass (in g) of 2.1 x 1024 atoms of W.

1 answer:

4 0

Atomic mass W = 183.84 u.m.a

183.84 g ----------- 6.02x10²⁴ atoms
?? g ---------------- 2.1x10²⁴ atoms

2.1x10²⁴ x 183.84 / 6.02x10²⁴ =

3.860x10²⁶ / 6.02x10²⁴ = 641.30 g

hope this helps!

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A gas is collected at 30 Celsius and has a pressure of 200 kPa. What pressure would it exert if the temperature changed to 40 Ce

garik1379 [7]

Answer:

$206.6\ \text{kPa}$

Explanation:

$P_1$ = Initial pressure = 200 kPa

$P_2$ = Final pressure

$T_1$ = Initial temperature = $30^{\circ}\text{C}$

$T_2$ = Final temperature = $40^{\circ}\text{C}$

We have the relation

$\dfrac{P_2}{P_1}=\dfrac{T_2}{T_1}\\\Rightarrow P_2=\dfrac{T_2}{T_1}P_1\\\Rightarrow P_2=\dfrac{40+273.15}{30+273.15}\times 200\\\Rightarrow P_2=206.6\ \text{kPa}$

The pressure that would be exerted after the temperature change is $206.6\ \text{kPa}$ .

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2 years ago

At the normal melting point of NaCl, 801 degrees C, its enthalpy of fusion is 28.8 kJ / mol. The density of the solid is 2.165 g

melisa1 [442]

<u>Answer:</u> The increase in pressure is 0.003 atm

<u>Explanation:</u>

To calculate the final pressure, we use the Clausius-Clayperon equation, which is:

$\ln(\frac{P_2}{P_1})=\frac{\Delta H}{R}[\frac{1}{T_1}-\frac{1}{T_2}]$

where,

$P_1$ = initial pressure which is the pressure at normal boiling point = 1 atm

$P_2$ = final pressure = ?

$\Delta H$ = Enthalpy change of the reaction = 28.8 kJ/mol = 28800 J/mol (Conversion factor: 1 kJ = 1000 J)

R = Gas constant = 8.314 J/mol K

$T_1$ = initial temperature = $801^oC=[801+273]K=1074K$

$T_2$ = final temperature = $(801+1.00)^oC=802.00=[802+273]K=1075K$

Putting values in above equation, we get:

$\ln(\frac{P_2}{1})=\frac{28800J/mol}{8.314J/mol.K}[\frac{1}{1074}-\frac{1}{1075}]\\\\\ln P_2=3\times 10^{-3}atm\\\\P_2=e^{3\times 10^{-3}}=1.003atm$

Change in pressure = $P_2-P_1=1.003-1.00=0.003atm$

Hence, the increase in pressure is 0.003 atm

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2 years ago

If you have 3.0 moles of argon gas at STP, how much volume will the argon take up?

Anestetic [448]

If you have 3.0 moles of argon gas at STP u would take up 2.5 volume

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2 years ago

The concentration of the stock solution she needs is 100 milli molar (mm) and she needs to make 1.2 milli liters (ml) solution o

Lera25 [3.4K]

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2 years ago