Answers
Answer:
The following is a rather lengthy discussion on chemical stoichiometry, but it will lead you through the mole concept and its application to chemical reaction stoichiometry. The problems are different than the one posted, but if you can follow this, then you can work your problem of interest.
Explanation:
Stoichiometry is very easy to master if you understand the ‘mole concept’ and how it is used to define and describe chemical process mathematically. A ‘mole’ – in chemistry – is the mass of substance containing one Avogadro’s Number of particles. That is, N₀ = 6.023 x 10²³ particles / mole. When working with chemical reactions and equations data should be first converted to moles using the following conversions.
1 mole = 1 formula weight = 6.023 x 10²³ particles = 22.4 liters at STP(0⁰, 1atm).
In this problem you are given the equation 2Na + 2H₂O => 2NaOH + H₂. ‘Reading the equation’ there are 2 moles of Na, 2 moles of water, 2 moles of NaOH and 1 mole of H₂. In another example 3H₂ + N₂ => 2NH₃ there are 3 moles of H₂, 1 mole of N₂ and 2 moles of NH₃. The mole values can be multiples or fractions but if one mole value increases all the remaining mole values increase or decrease proportionally. For example:
Using the equation 2Na + 2H₂O => 2NaOH + H₂, one could multiply the equation by 2 giving 4Na + 4H₂O => 4NaOH + 2H₂. The equation shows balance but is not in standard form. If one multiplies the equation by ½ gives Na + H₂ => NaOH + ½H₂. Again, the equation shows balance but is not in standard form.
Standard form of equation also implies the equation conditions are at 0⁰C & 1atm pressure and 1 mole of any gas phase substance occupies 22.4 Liters volume. Such is the significance of converting given data to moles as all other substance mass (in moles) are proportional.
1st problem, 1.76 x 10²⁴ formula units of Na will react with water (usually read as an excess) to produce (?) grams of H₂.
1st write the equation followed by listing the givens below the respective formulas… That is…
Na + H₂O => NaOH + H₂,
Given: 1.76 x 10²⁴ atoms excess --------- ? grams
= 1.76 x 10²⁴atoms/6.023 x 10²³atoms/mole
= 2.922moles produces => 2.922moles H₂ (b/c coefficients of Na & H₂ are same)
Convert moles to grams => 2.922moles H₂ x 2.000 grams H₂/mole H₂
= 5.8443 grams H₂
2nd problem, 3.5 moles Na will react with H₂O (in excess) to produce (?) moles of NaOH.
Again, write equation and assign values to each formula unit in the equation.
Na + H₂O => NaOH + H₂,
Given: 3.5moles excess ? grams ----
Since coefficients of balanced std equation are equal …
3.5 moles Na produces => 3.5 moles NaOH
Convert moles to grams => 3.5 moles NaOH x 40 g Na/mole Na
= 140 grams NaOH
3rd problem, 2.75 x 10²⁵ molecules H₂O will react with (?) atoms of Na.
Same procedure, convert to moles, solve problem by ratios then convert to needed dimension at end of problem.
Na + H₂O => NaOH + H₂
Given: excess 2.75 x 10²⁵ molecules H₂O => ? atoms NaOH ----
Convert to moles => 2.75 x 10²⁵ molecules H₂O / 6.023 x 10²³ molecules H₂O/mole H₂O
= 45.658 moles H₂O => 45.658 moles NaOH (coefficients are equal)
Convert moles NaOH to grams NaOH => 45.658 moles NaOH x 40 grams NaOH/mole NaOH
= 1826.33 grams NaOH
Master the mole concept and you master a lot of chemistry! Good luck.
Related Questions
3. Move the slider on the burette to the top to add about 25 mL of NaOH to the flask. What
happens, and what does this tell you about the pH of the flask?
Page Break
LED
Answers
Answer:
When you move the burette slider to the top of a flask and add about 25 mL of NaOH to the flask, you will cause a concentration of OH- molecules. This will make the solution become a basic solution and make the litmus paper blue.
Explanation:
After reading your question, we can see that you are carrying out a test to discover the nature of the pH of a solution. This type of test uses litmus paper, which is an indicator of the presence of acids and bases, being able to determine the pH of a solution. This paper is soaked in organic ink and when placed in an acidic solution, it is red in color. However, when placed in a basic solution it has a blue color.
An acidic solution is one that has a high concentration of H+ atoms and has the ability to donate electrons. The basic solution, on the other hand, has a high concentration of OH- and has the capacity to receive electrons.
When you move the burette slider to the top of a flask and add about 25 mL of NaOH to the flask, you will cause a concentration of OH- molecules. This will make the solution become a basic solution and make the litmus paper blue, that is, the solution has the basic pH.
what is modal class?
தமிழ் வாழ்க
Answers
Answer:
Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency.
Answer:
Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency. For example: if you counted the number of pencils in different pencil cases and you decided to group them.
Explanation:
தமிழன் ❤
1. What is the molarity of an HCl solution if 50.0 mL of it is neutralized in a titration by
40.0 mL of 0.400 M NaOH? (0.32)
Answers
Answer:
C1 * V1 = C2 * V2
Explanation:
Where ‘C’ and ‘V’ refer to concentration and volume, ‘1’ and ‘2’ to solution 1 and 2 respectively. So, if ‘1’ refers to the HCl solution, we want to solve this equation for C1.
V1 = (C2*V2)/C1 = (0.4 * 50)/40 = 0.5 M
Select the word that fits in the two blanks below: This is made up of two systems; a central ________ system and a peripheral ___________ system.
Answers
Answer:
Nervous; nervous.
Explanation:
A sensory system can be defined as components of the central nervous system (CNS) which comprises of the brain, neural tissues or pathways and sensory neurons responsible for sensory functions, perception and processing sensory informations such as sound, light, heat, etc.
Basically, the central nervous system (CNS) interprete the neural signals that are generated from stimuli that are detected by the sensory system. The five (5) main sense organs in the sensory system are: skin, tongue, ears, nose and the eyes.
Generally, the nervous system found in living organisms such as humans, comprises of two (2) major components or systems; a central nervous system (CNS) and a peripheral nervous system (PNS).
Black coffee has a pH of around 5. Since pH and pOH have an inverse relationship, black coffee has a pOH of ___.
Answers
Answer:
pOH = 9.
Explanation:
The inverse relationship between the pH and pOH of any given solution can be written as:
pH = 14 - pOH
Or conversely:
pOH = 14 - pH
With the above information in mind we can use the given pH to calculate the pOH:
pOH = 14 - pH
pOH = 14 - 5
pOH = 9
Thus, black coffee has a pOH of 9.
Why are large crystals of sodium chloride used instead of small
crystals when making ice cream
Answers
Answer:
Sodium chloride is added to the ice to lower the freezing point of the ice. Large crystals dissolve more slowly than small crystals. This allows time for the ice cream to freeze more evenly.
Explanation:
72.3 g of ice at -15.0 o C has heat energy added to it until it becomes steam at 145 o C. Calculate the total amount of heat energy needed (in Joules) to accomplish this.
Answers
Answer:
H = 226,311.66J
Explanation:
Hello there!
In this case, according to the thermodynamic path ice takes up to steam:
1. Ice (-15°C) --> Ice (0°C) H1
2. Ice (0°C) ---> Water (0°C) H2
3. Water (0°C) --> Water (100°C) H3
4. Water (100°C) --> Steam (100°C) H4
5. Steam (100°C) --> Steam (145°C) H5
It is possible for us to infer that H1, H3 and H5 are computed by means of the mass, specific heat and change in temperature as sensible heat. On the flip side, H2 and H4 are computed as latent heat. Thus, we proceed as follows:
[tex]H1=72.3g*2.093\frac{J}{g\°C}(0+15)\°C=2269.86J\\\\H2=72.3g*334.1\frac{J}{g}=24155.43J\\\\H3=72.3g*4.184 \frac{J}{g\°C}*(100-0)\°C=30250.32J\\\\H4=72.3g*2255.83\frac{J}{g}=163096.51J\\\\H5=72.3g* 2.010 \frac{J}{g\°C}*(145-100)\°C=6539.54J[/tex]
Then, we add them up to obtain the total heat:
[tex]H=H1+H2+H3+H4+H5\\\\H=2269.86J+24155.43J+30250.32J+163096.51J+6539.54J\\\\H=226311.66J[/tex]
Best regards!
Which of the following is not a force
A. Weight
B. Friction
C. Acceleration
D. Air resistance
Answers
Answer:
Acceleration
Explanation:
Acceleration doesn't change one moment to the next, and therefore, doesn't count as a force.
The answer option which is not a force is: C. Acceleration.
What is a force?A force can be defined as a push or pull of an object or physical body, which typically results in a change of motion (acceleration), especially due to the interaction of the object with another.
The examples of a force.In Science, the three (3) most common examples of a force include the following:
WeightFrictionAir resistanceIn conclusion, acceleration is not an example of a force but a change in the rate of velocity of an object with respect to time.
Read more on force here: brainly.com/question/1121817
Describe how the freeze-thaw cycle of ice will change the shape of this rock over time. PLSSSS HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!✋
Answers
Freeze-Thaw Weathering
This action can widen the cracks in the rock, and when the temperature rises above freezing, the ice thaws, allowing the water to seep further into the cracks. As this process of freezing and thawing happens repeatedly, the rock begins to weaken and eventually breaks apart into angular fragments.
Answer:
Physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water. ... Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
Explanation:
hope this helps
Explain the equilibrium law as it relates to chemical equilibrium. Describe the types of stresses that cause chemical reactions in equilibrium to make more products.
Answers
When a reaction has reached equilibrium with a given set of conditions, if the conditions are not changed, the reaction will remain at equilibrium forever. The forward and reverse reactions continue at the same equal and opposite rates and the macroscopic properties remain constant.
It is possible, however, to disturb that equilibrium by changing conditions. For example, you could increase the concentration of one of the products, or decrease the concentration of one of the reactants, or change the temperature. When a change of this type is made within a reaction at equilibrium, the reaction is no longer in equilibrium. When you alter something in a reaction at equilibrium, chemists say that you put stress on the equilibrium. When this occurs, the reaction will no longer be in equilibrium and the reaction itself will begin changing the concentrations of reactants and products until the reaction comes to a new position of equilibrium. How a reaction will change when a stress is applied can be explained and predicted. That is the topic of this section.
What volume of solution is required to produce a 7.8M solution containing 23.6g of LiBr?
Answers
Answer:
34.9 mL
Explanation:
First we convert 23.6 g of LiBr into moles, using its molar mass (86.845 g/mol):
23.6 g ÷ 86.845 g/mol = 0.272 mol LiBrNow we can calculate the required volume, using the definition of molarity:
Molarity = moles / litersliters = moles / Molarity0.272 mol / 7.8 M = 0.0349 LWe can convert L into mL:
0.0348 L * 1000 = 34.9 mLwhat is the number of moles of solute in 250 mL of a .80M solution
Answers
Answer:
There are 0.1 moles of solute in 250 mL of 0.4 M solution
Explanation:
because it is
1. Which is a chemical property of wood?
conductivity
flammability
malleability
Answers
Answer:
Wood consists mainly of organic substances (99% of the total mass). Elemental chemical composition of wood of different breeds is practically the same. Absolutely dry wood on average contains 49% of carbon, 44% of oxygen, 6% of hydrogen, 0.1-0.3% of nitrogen. When burning wood remains its inorganic part - ash.
So the answer is flammability because wood is flammable.
the pressure of a 250.0 mL volume of gas under 4.0 atm of pressure is decreased to 1.0 atm at constant tempture what is a new volume
Answers
Answer:
1000 mLExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we're finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{250 \times 4}{1} = 1000 \\ [/tex]
We have the final answer as
1000 mLHope this helps you
Net ionic equation for sodium carbonate and sulfuric acids?
Answers
Answer:
CO₃²¯(aq) + 2H⁺(aq —> H₂O(l) + CO₂(g)
Explanation:
The net ionic equation for sodium carbonate (Na₂CO₃) and sulfuric acid (H₂SO₄) can be obtained as follow:
Na₂CO₃ + H₂SO₄ —>
In solution, Na₂CO₃ and H₂SO₄ will dissociate as follow:
Na₂CO₃(aq) —> 2Na⁺(aq) + CO₃²¯(aq)
H₂SO₄(aq) —> 2H⁺(aq) + SO₄²¯(aq)
Na₂CO₃(aq) + H₂SO₄(aq) —>
2Na⁺(aq) + CO₃²¯(aq) + 2H⁺(aq) + SO₄²¯(aq) —> 2Na⁺(aq) + SO₄²¯(aq) + H₂O(l) + CO₂(g)
Cancel out the spectator ions (i.e Na⁺ and SO₄²¯) to obtain the net ionic equation.
CO₃²¯(aq) + 2H⁺(aq —> H₂O(l) + CO₂(g)
If you wanna get oil to 180 celcius when it starts at 20 how many units of thermal energy is needed?
Answers
Answer:
The thermal energy (heat) needed, to raise the temperature of oil of mass 'm' kilogram and specific heat capacity 'c' from 20°C to 180°C is 160·m·c joules
Explanation:
The heat capacity, 'C', of a substance is the heat change, ΔQ, required by a given mass, 'm', of the substance to produce a unit temperature change, ΔT
∴ C = ΔQ/ΔT
ΔQ = C × ΔT
C = m × c
Where;
c = The specific heat capacity
ΔT = The temperature change = T₂ - T₁
∴ ΔQ = m × c × ΔT
Therefore, the thermal energy (heat) needed, ΔQ, to raise the temperature of oil of mass 'm' kilogram and specific heat capacity, 'c' from 20°C to 180°C is given as follows;
ΔQ = m × c × (180° - 20°) = 160° × m·c
ΔQ = 160·m·c joules
During a tug-of-war, the rope accelerates towards the left. What is true about the forces acting on the rope?
Answers
Explanation:
Forces are given many names, such as push, pull, thrust, lift, weight, friction, and tension. Traditionally, forces have been grouped into several categories and given names relating to their source, how they are transmitted, or their effects. The most important of these categories are discussed in this section, together with some interesting applications. Further examples of forces are discussed later in this text.
How do different chemical reactions interact with the surrounding environment?
Answers
Answer:
The earth is made of chemical
Explanation:
Explanation:
because of the chemical made up with earth
what are the factors that affect the rate of chemical reaction?
Answers
Answer:
surface area of a solid reactant.
concentration or pressure of a reactant.
temperature.
nature of the reactants.
presence/absence of a catalyst.
Weathering (breaking off sediments upriver), erosion (moving the sediments down river) and finally deposition caused the changes in the river.
What helps hold sediments in place to prevent erosion?
Answers
Answer:
Explanation:
Maintaining a healthy, perennial plant cover.
Mulching.
Planting a cover crop – such as winter rye in vegetable gardens. ...
Placing crushed stone, wood chips, and other similar materials in heavily used areas where vegetation is hard to establish and maintain.???
TRUE OR FALSE
Astronomers use spectroscopes to identify elements in stars because each element produces
unique emission spectrum
Answers
Answer:
True!
Explanation:
A spectrum is simply a chart or a graph that shows the intensity of light being emitted over a range of energies. Have you ever seen a spectrum before? Probably. Nature makes beautiful ones we call rainbows. Sunlight sent through raindrops is spread out to display its various colors (the different colors are just the way our eyes perceive radiation with slightly different energies).
Hope i helped!
List the methods of separation used in water purification...... ( HELP PLEASE )
Answers
Answer:
I can list four. These are the main ones.
Bolling
Filtration
Distillation.
Chlorination
Explanation:
if the original volume of a gas was 300 ml at 0.250 atm and 400.0 k what is the volume of the gas at 2.00 atm
Answers
Answer:
the answer is 18.75
4. The speed of a wave is 75m/s. If the wavelength of the wave is 5m, what is the frequency of the
wave?
Answers
Answer:
15Hz
Explanation:
75m/s / 5m = 15Hz
I hope this helps u! :D
Answer: 15?
Explanation: You take the formula of velocity=length/frequency and change it to velocity/length=frequency to accommodate the values you have.
Name the following acid: HNO3
Answers
Answer:
Nitric Acid
Explanation:
Also known as aqua Fortis and spirt of niter
Hope it helps
Answer:
Nitric Acid
Explanation:
"Nitric acid (HNO3), also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water."
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Hope I Helped, Feel free to ask any questions to clarify :)
Have a great day!
More Love, More Peace, Less Hate.
-Aadi x
What is happening when an oxygen molecule is formed from two separate oxygen atoms?
Answers
Answer:
They form a double bond
Explanation:
Given the reaction: HNO2 (aq) <-> H+ (aq) + NO2- (aq); write the ionization constant for the reaction.
Answers
Answer:
see explanation
Explanation:
HNO₂ ⇄ H⁺ + NO₂⁻
Ka = [H⁺][NO₂⁻]/[HNO₂]
HELP a #QUEEN out pls??
Type the correct answer in each box.
Balance the equation.
_____SiO2 + ______CaC2 → _____Si + _______CaO + _____CO2
Answers
The coefficients, in order of the blanks, are 5, 2, 5, 2, 4.
What is the correct term for a community of plants and animals and their physical surroundings?
individuals (organism)
continent
territory
ecosystem
Answers
Can someone please please help me please
Answers
Explanation:
there is what i got hope it helps. ❤❤❤❤❤
