Can someone pls help, I’m sorry if it’s a lot

A particular balloon can be stretched to a maximum surface area of 1257 cm2. The balloon is filled with 3.1 L of helium gas at a

lianna [129]

Answer:

P = 0.6815 atm

Explanation:

Pressure = 754 torr

The conversion of P(torr) to P(atm) is shown below:

$P(torr)=\frac {1}{760}\times P(atm)$

So,

Pressure = 754 / 760 atm = 0.9921 atm

Temperature = 294 K

Volume = 3.1 L

Using ideal gas equation as:

PV=nRT

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

0.9921 atm × 3.1 L = n × 0.0821 L.atm/K.mol × 294 K

⇒n of helium gas= 0.1274 moles

Surface are = 1257 cm²

For a sphere, Surface area = 4 × π × r² = 1257 cm²

r² = 1257 / 4 × π ≅ 100 cm²

r = 10 cm

The volume of the sphere is :

$V=\frac {4}{3}\times \pi\times r^3$

Where, V is the volume

r is the radius

$V=\frac {4}{3}\times \frac {22}{7}\times {10}^3$

V = 4190.4762 cm³

1 cm³ = 0.001 L

So, V (max) = 4.19 L

T = 273 K

n = 0.1274 moles

Using ideal gas equation as:

PV=nRT

Applying the equation as:

P × 4.19 L = 0.1274 × 0.0821 L.atm/K.mol × 273 K

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4 0

2 years ago

When 15.3 g of sodium nitrate, NaNO3,was dissolved in water in a calorimeter, the temperature fell from 25.00oC to 21.56oC. If t

satela [25.4K]

Answer:

20.468 kilo Joules is the enthalpy change when one mole of sodium nitrate dissolves.

Explanation:

Heat lost by solution ad calorimeter = Q

Heat capacity of solution ad calorimeter = C = 1071 J/°C

Change in temperature = ΔT = 21.56°C - 25.00°C = -3.44°C

$Q=C\times Delta T$

$Q=1071 J/^oC\times (-3.44^oC)=-3,684.24 J$

Heat gained by sodium nitrate = -Q = -(-3,684.24 J)=3,684.24 J

Moles of sodium nitrate = $\frac{15.3 g}{85 g/mol}=0.18 mol$

When 0.18 mole of sodium nitrate was dissolved in water 3,684.24 joulesof heat was absorbed by it.

Then heat absorbed by 1 mole of sodium nitrate :

$\frac{3,684.24 J}{0.18}=20,468 J=20.468 kJ$

1 J = 0.001 kJ

20.468 kilo Joules is the enthalpy change when one mole of sodium nitrate dissolves.

8 0

2 years ago

TIME REMAINING 52:03 Considering the activity series given below for metals and nonmetals, which reaction will occur?

Luden [163]

Answer:

2NaBr + I2 Right arrow. 2NaI + Br2

2AgNO3 + Ni Right arrow. Ni(NO3)2 + 2Ag

Explanation:

The activity or electrochemical series is an arrangement of elements according to their order

of reactivity.

If we look at the reactions, one thing that we must note is that the reactions that can occur are those in which an element that is higher in the series displaces another element that is lower in the series.

Br is higher in the electrochemical series than I so it can displace it. Ni is higher than Ag in the electrochemical series hence it can displace it.

7 0

2 years ago

Read 2 more answers

MARKING BRAINLIEST :)

Reil [10]

Answer:

a

Explanation:

3 0

2 years ago

The model on the right looks bumpy, but when you break a large salt crystal in two, the edges of the split often look straight a

emmasim [6.3K]

There is no problem with the model formed by atoms as solid spheres for macroscopic measurements because the atoms are extremely small.

<h3>What is Dalton's atomic model?</h3>

This was formulated in 1808 and states that atoms with spheres cannot be divided. It also states that solids are formed by contact between the spheres and chemical compounds from joining of atoms of two or more elements.

The size of the atoms in the form of sphere is very small as it is known that it is of the order of 10⁻⁹ m, therefore, having a macroscopic crystal more than 10⁻⁶ m in length which is why the model of the atom as solid spheres for macroscopic measurements has no problem.

Read more about Dalton's atomic theory here brainly.com/question/13157325

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5 0

7 months ago