1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Leno4ka [110]
4 years ago
11

If the reaction of 4.50 moles of sodium with excess hydrofluoric acid produced an 85.0% yield of hydrogen gas, what was the actu

al yield of hydrogen gas? Unbalanced equation: Na + HF “yields”/ NaF + H2 1.91 mol H2 2.25 mol H2 2.65 mol H2 3.82 mol H2
Chemistry
2 answers:
hram777 [196]4 years ago
8 0
First  write a balanced  chemical  equation
that  is  2Na +2Hf  --->2Naf  +H2
This  implies  that  to  moles  2 of  Na  reacted  with 2 moles  of HF  to  form  2 moles  of  Naf  and  1  mole  of  H2
thus  the  mole  of  H2  =4.50  x1/2= 2.25moles  of  H2

Illusion [34]4 years ago
5 0
<span>1.91 mol H2 Let's rewrite that equation into a balanced equation. Let's start with the unbalanced version: Na + HF ==> NaF + H2 We have equal amounts of Na and F on both sides, but twice as much H on the right. So let's double the Na, HF, and NaF coefficients. 2Na + 2HF ==> 2NaF + H2 And we now have equal quantities of all elements on both sides, so our equation is balanced. Now looking at the balanced equation, 2 moles of sodium should produce 1 mole of hydrogen gas. So we should have 4.50/2 = 2.25 moles of hydrogen gas. But we only have an 85% yield, so we multiply the expected yield by the percentage, giving 2.25 mol * 0.85 = 1.9125 mol. Rounding to 3 significant figures gives us 1.91 mol which matches "1.91 mol H2"</span>
You might be interested in
How many helium nuclei fuse together when making carbon?
Gemiola [76]
The answer is the 3. Hope this helped!
8 0
3 years ago
At sea level, where the pressure was 104 kPa and temperature 21.1 ºC, a certain mass of air occupies 2.0 m3 . To what volume wil
Romashka [77]

Answer:

The volume of air at where the pressure and temperature are  52 kPa, -5.0 ºC is 3.64 m^3.

Explanation:

The combined gas equation is,

\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}

where,

P_1 = initial pressure of gas = 104 kPa

P_2 = final pressure of gas = 52 kPa

V_1 = initial volume of gas = 2.0m^3

V_2 = final volume of gas = ?

T_1 = initial temperature of gas = 21.1^oC=273+21.1=294.1K

T_2 = final temperature of gas = -5.0^oC=273+(-5.0)=268 K

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

\frac{104 kPa\times 2.0m^3}{294.1 K}=\frac{52 kPa\times V_2}{268 K}

V_2=3.64 m^3

The volume of air at where the pressure and temperature are  52 kPa, -5.0 ºC is 3.64 m^3.

3 0
3 years ago
Describe one example of an energy transformation in this diagram and explain why it is a transformation. Repeat this description
iren [92.7K]

Answer:

The conservation of energy principle states that energy can neither be destroyed nor created. Instead, energy just transforms from one form into another. So what exactly is energy transformation? Well, as you might guess, energy transformation is defined as the process of changing energy from one form to another. There are so many different kinds of energy that can transform from one form to another. There is energy from chemical reactions called chemical energy, energy from thermal processes called heat energy, and energy from charged particles called electrical energy. The processes of fission, which is splitting atoms, and fusion, which is combining atoms, give us another type of energy called nuclear energy. And finally, the energy of motion, kinetic energy, and the energy associated with position, potential energy, are collectively called mechanical energy. That sounds like quite a lot, doesn't it? Well it is, but don't worry, it's actually all pretty easy to remember. Next, we'll explore all of these kinds of possible transformations in more detail. Different Types of Energy Transformations Chemical energy is the energy stored within a substance through the bonds of chemical compounds. The energy stored in these chemical bonds can be released and transformed during any type of chemical reaction. Think of when you're hungry. When you eat a piece of bread to satisfy this hunger, your body breaks down the chemical bonds of the bread and uses it to supply energy to your body. In this process, the chemical energy is transformed into mechanical energy, which you use to move, and which we'll cover in more detail in a moment. It also transforms it into thermal energy, which is created through the metabolic processes in your body to generate heat. Most of the time, chemical energy is released in the form of heat, and this transformation from chemical energy to heat, or thermal energy, is called an exothermic reaction. Next, there are two main types of mechanical energy: kinetic energy and potential energy. Kinetic energy is the energy associated with the motion of an object. Therefore, any object that moves has kinetic energy. Likewise, there are two types of potential energy: gravitational potential energy and elastic potential energy. Gravitational potential energy is associated with the energy stored by an object because of its location above the ground. Elastic potential energy is the energy stored by any object that can stretch or compress. Potential energy can be converted to kinetic energy and vice versa. For example, when you do a death-defying bungee jump off of a bridge, you are executing a variety of energy transformations. First, as you prepare to jump, you have gravitational potential energy - the bungee cord is slack so there is no elastic potential energy. Once you jump, you convert this gravitational potential energy into kinetic energy as you fall down. At the same time, the bungee cord begins to stretch out. As the cord stretches, it begins to store elastic potential energy. You stop at the very bottom when the cord is fully stretched out, so at this point, you have elastic potential energy. The cord then whips you back up, thereby converting the stored elastic potential energy into kinetic energy and gravitational potential energy. The process then repeats

Explanation:

here u go :P

8 0
3 years ago
Read 2 more answers
How many liters of air must react with 2500 mL of hexane in order for combustion to occur completely. The percentage of oxygen i
bagirrra123 [75]

Answer:

118750 ml

Explanation:

The chemical equation for complete combustion of hexane is given as;

2C6H14 + 19O2 → 12CO2 + 14H2O  

From the equation of the reaction;

2 mol of C6H14 reacts with 19 mol of O2

2 ml of C6H14 reacts with 19 ml of O2

2500 mL of C6H14 would react with x ml of O2

2 = 19

2500 = x

x = 2500 * 19 / 2 = 23750 ml

Since oxygen is 20% of air;

23750 = 20 / 100 * (Volume of air)

Volume of air = 23750 * 100 / 20 = 118750 ml

7 0
3 years ago
Which is bigger 145 m or 145 km
Citrus2011 [14]
145 km i think is bigger
8 0
3 years ago
Read 2 more answers
Other questions:
  • If the percent (mass/mass) for a solute is 8% and the mass of the solution is 200 g, what is the mass of solute in solution?
    11·2 answers
  • In order to complete a lab, your teacher needs a 3.0 M solution of sulfuric acid, but only has a 12.0 M stock solution of sulfur
    14·1 answer
  • What is the product of 3 x 10² kg and 2 x 10-3<br> kg?
    15·1 answer
  • Explain why the weight of an object is different on earth and on moon even though the objects mass is the same in both place.
    13·2 answers
  • A jeweler has five rings, each weighing g, made of an alloy of silver and gold. She decides to melt down the rings and add enoug
    10·1 answer
  • What is formed when water chemically combines with carbon dioxide
    11·1 answer
  • What is the first element in the periodic table?
    12·2 answers
  • What is the mass of disulfur pentoxide (S2O5)?
    11·1 answer
  • What quantity of energy is required to heat a piece of iron wighing 1.31 g from 25.0 degrees celsius to 46.0 degrees celsius
    15·1 answer
  • What kind of weather is associated with high air pressure?
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!