Element+element examples

How many molecules of CO2 at standard temperature and pressure in 5.4 moles of CO2

olganol [36]

Answer:

3.25×10²⁴ molecules.

Explanation:

From the question given above, the following data were obtained:

Number of mole of CO₂ = 5.4 moles

Number of molecules of CO₂ =?

The number of molecules of CO₂ in 5.4 moles can be obtained as follow:

From Avogadro's hypothesis,

1 mole of CO₂ = 6.02×10²³ molecules

Therefore,

5.4 moles of CO₂ = 5.4 × 6.02×10²³

5.4 moles of CO₂ = 3.25×10²⁴ molecules

Thus, 5.4 moles of CO₂ contains 3.25×10²⁴ molecules.

8 0

3 years ago

If two poisonous elements are combined chemically, which of the following will be true of the resulting compound?

andrew11 [14]

the compound would not be poisonous because of the properties of the two compounds

4 0

4 years ago

Read 2 more answers

A ball is thrown in the air. The ball goes up, then changes direction and falls down. Why does the ball fall down?

Delicious77 [7]

So the acceleration has actually slowed down the ball because it was going in the direction opposite the velocity. Now see what happens as the ball falls back down to Earth. The ball has zero velocity, but the acceleration due to gravity accelerates the ball downward at a rate of –9.8 m/s2.

hope it helps

7 0

3 years ago

What volume of nitrogen dioxide is formed at 735 torr and 28.2 °C by reacting 3.56 cm3 of copper (d = 8.95 g/cm3) with 200 mL of

weqwewe [10]

Answer:

25.76 L

Explanation:

Given, Volume of Copper = 3.56 cm³

Density = 8.95 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 8.95 g/cm³ * 3.56 cm³ = 31.862 g

Mass of copper = 31.862 g

Molar mass of copper = 63.546 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{31.862\ g}{63.546\ g/mol}$

<u>Moles of copper = 0.5014 moles </u>

Given, Volume of nitric acid solution = 200 mL = 200 cm³

Density = 1.42 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 1.42 g/cm³ * 200 cm³ = 284 g

Also, Nitric acid is 68.0 % by mass. So,

Mass of nitric acid = $\frac {68}{100}\times 284\ g$ = 193.12 g

Molar mass of nitric acid = 63.01 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{193.12\ g}{63.01\ g/mol}$

<u>Moles of nitric acid = 3.0649 moles </u>

According to the reaction,

$Cu_{(s)}+4HNO_3_{(aq)}\rightarrow Cu(NO_3)_2_{(aq)} + 2NO_2_{(g)} + 2H_2O_{(l)}$

1 mole of copper react with 4 moles of nitric acid

Thus,

0.5014 moles of copper react with 4*0.5014 moles of nitric acid

Moles of nitric acid required = 2.0056 moles

Available moles of nitric acid = 3.0649 moles

<u>Limiting reagent is the one which is present in small amount. Thus, nitric acid is present in large amount, copper is the limiting reagent. </u>

The formation of the product is governed by the limiting reagent. So,

1 mole of copper on reaction forms 2 moles of nitrogen dioxide

So,

0.5014 mole of copper on reaction forms 2*0.5014 moles of nitrogen dioxide

<u>Moles of nitrogen dioxide = 1.0028 moles </u>

Given:

Pressure = 735 torr

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

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

So,

Pressure = 735 / 760 atm = 0.9632 atm

Temperature = 28.2 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T₁ = (28.2 + 273.15) K = 301.35 K

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:

0.9632 atm × V = 1.0028 mol × 0.0821 L.atm/K.mol × 301.35 K

4 0

3 years ago

A 13-gram rubber stopper is attached to a 0.93-meter

makkiz [27]

<h3>Answer:</h3>

The centripetal acceleration is 26.38 m/s²

<h3>Explanation:</h3>

We are given;

Mass of rubber stopper = 13 g
Length of the string(radius) = 0.93 m
Time for one revolution = 1.18 seconds

We are required to calculate the centripetal acceleration.

To get the centripetal acceleration is given by the formula;

Centripetal acc = V²/r

Where, V is the velocity and r is the radius.

Since time for 1 revolution is 1.18 seconds,

Then, V = 2πr/t, taking π to be 3.142 ( 1 revolution = 2πr)

Therefore;

Velocity = (2 × 3.142 × 0.93 m) ÷ 1.18 sec

= 4.953 m/s

Thus;

Centripetal acceleration = (4.953 m/s)² ÷ 0.93 m

= 26.38 m/s²

Hence, the centripetal acceleration is 26.38 m/s²

6 0

3 years ago