Determine the empirical and molecular formulas of the mandelic acid
Answer:
Both empirical and molecular are C₈H₈O₃.
Explanation:
Hello!
In this case, according the attached picture, it is possible to figure out the molecular formula of the mandelic acid by counting each carbon, hydrogen and oxygen in the molecule.
In such a way, we can see the presence of eight carbon atoms, eight hydrogen atoms and three carbon atoms; thus, the molecular formula is:
C₈H₈O₃
Furthermore, since the empirical formula is the smallest representation of the molecular formula when we are able to simplify it, we evidence no simplification is possible, consequently, the empirical formula equals the molecular one.
Best regards!
२
1. A ratio of the parts of a mixture are exact true or false.
Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound
Answer:
No, compound A and B are not the same compound
Explanation:
According to the law of definite proportion "every chemical compound contains fixed and constant proportions (by mass) of its constituent elements." (Encyclopedia Britannica)
We can see in the question that the ratio of flourine to sulphur in compound A is 1.18 while the ratio of flourine to sulphur in compound B is 2.37.
The two chemical compounds do not contain a fixed proportion by mass of their constituent elements therefore, they can not be same compound according to the law of definite proportions.
A 0.90 g of hydrogen chloride (HCl) is dissolved in water to make 5.0 L of solution. What is the pH of the resulting hydrochloric acid solution?
Express the pH numerically to two decimal places.
0.50g of sodium hydroxide (NaOH) pellets are dissolved in water to make 4.0L of solution. What is the pH of this solution?
Express the pH numerically to two decimal places.
Answer:
Explanation:
Mol weight of HCl = 36.5
.90 g of HCl = .90 / 36.5 mole = .02465 mole
HCl = H⁺ + Cl⁻
1 mole 1 mole
1 mole of HCl gives 1 mole of H⁺
.02465 mole of HCl will give .02465 mole of H⁺
.02465 mole of H⁺ in 5 litre soln
concentration of H⁺ = .02465 / 5 = 4.93 x 10⁻³ M
pH = - log ( 4.93 x 10⁻³ )
= 3 - log 4.93
= 3 - .693
= 2.307
= 2.31
NaOH :
Mol weight of NaOH = 40
.50 g of HCl = .50 / 40 mole = .0125 mole
NaOH = Na⁺ + OH⁻
1 mole 1 mole
1 mole of NaOH gives 1 mole of OH⁻
.0125 mole of NaOH will give .0125 mole of OH⁻
.0125 mole of OH⁻ in 4 litre soln
concentration of OH⁻ = .0125 / 4 = 3.125 x 10⁻³ M
pOH = - log ( 3.125 x 10⁻³ )
= 3 - log 3.125
= 3 - .495
= 2.505
pH = 14 - pOH
= 14 - 2.505
= 11.495 .
= 11.50
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
Answer:
the change in energy of the gas mixture during the reaction is 227Kj
Explanation:
THIS IS THE COMPLETE QUESTION BELOW
Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.
From thermodynamics
ΔE= q + w
Where w= workdone on the system or by the system
q= heat added or remove
ΔE= change in the internal energy
q=+ 319kJ ( absorbed heat is + ve
w= -92kJ
If we substitute the given values,
ΔE= 319 + (-92)= 227 Kj
With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.
This is the chemical formula for Chormium (III) nitrate Cr(NO3)3Calculate the mass percent of nitrogen in chromium(III) nitrate.
Answer:
The percent composition for nitrogen in chromium(III) nitrate is 6%.
Explanation:
The mass percent of nitrogen in chromium(III) nitrate is 17.655%.
Calculation,
Molar mass of one oxygen = 16 g
molar mass of nine oxygen = 9 × 16 g = 144 g
molar mass of one nitrogen atom = 14 g
molar mass of three nitrogen atom = 3 × 14 g = 42 g
molar mass of one chromium atom = 51.99 g
molar mass of chromium (III) nitrate molecule = 144 g + 42 g + 51.99 g = 237.99 g
Mass percent of nitrogen = mass of three nitrogen atom× 100 /mass of chromium(III)nitrate
Mass percent of nitrogen = 42 g/237.99 g × 100 = 17.655%
What is mass percentage?The percentage of the mass of the element or solute divided by the mass of the compound or solute is called mass percentage
learn about mass percentage,
https://brainly.com/question/16885872
#SPJ2
What do atoms make up
Question 2 2 points)
Which of the atoms shown has an atomic number of 42
1
2
4
7
Answer:
4 is the answer
Explanation:
i am not sure for this question
Which gland in the human body is a part of two human body systems (Digestive &
Endocrine)?
A. Testes
B. Ovaries
C. Both
D. Pancreas
Answer: D pancreas
Explanation: testes are for male ovary are for female one human can have both
PLEASE HURRY. This is a project please help me as soon as possible.
1. What do you think would have happened if the light pollution had been a permanent condition
on planet Oopsa?
2. What do you think would have happened if the light pollution were green instead of red?
Please help asap. Will give brainliest.
Answer:
Light pollution is excessive, misdirected or inappropriate outdoor lighting. Too much light pollution washes out the view of the Universe, increasing energy consumption, interferes with astronomical research, disrupts ecosystems, and affects the health and safety of humans and wildlife.
Explanation:
Light pollution radically alters their nighttime environment by turning night into day. ... “Predators use light to hunt, and prey species use darkness as cover,” Kyba explains “Near cities, cloudy skies are now hundreds, or even thousands of times brighter than they were 200 years ago.
Where did the magma and sediment that formed the rock of the Great Plains and the Rocky
Mountains come from?
Which claim do you think is more likely to be true?
Claim 1: The sediment that formed the Great Plains came from the rock of the Rocky
Mountains.
Claim 2: The magma that formed the Rocky Mountains came from the rock of the Great Plains.
Answer:
1
Explanation seems right
The magma and sediments formed in the great plains are came from the rocks of the rocky mountains. Therefore, claim 1 is correct.
What is sedimentation?Sedimentation is the geographical process of accumulation or deposition of the minerals and organic particles from the earth's surface is called sedimentation. This process results in the formation of sedimentary rocks.
Weathering or erosion of rocks by wind, water or other chemicals leads to the geological debris which then move to other places deposits somewhere.
Rocks in the rocky mountains undergo erosion and the mass movements created by wind or water leads to the sedimentation of these rocky solids to other places. The rocks in the Great planes are reached there by the mass movement of the rocks of rocky mountains. Hence, claim 1 is correct.
To find more on sedimentation, refer here:
https://brainly.com/question/14306913
#SPJ5
2. Which of the following could the flame test be used for?
Each polysaccharide tested gives different color results with the iodine test
If a solution containing 24.0 g of a substance reacts by first-order kinetics, how many grams remain after three half-lives?
Answer:
3.0g remain
Explanation:
The half-life is defined as the time required for a reactant to decrease its concentration in exactly the half of the initial amount of reactant. Having this in mind:
In one half-life, the mass will be:
24.0g / 2 = 12.0g
In two half-lifes:
12.0g / 2 = 6.0g
And in three half-lifes, the mass that remain is:
6.0g / 2 =
3.0g remainBoth magnetic fields and electric fields can exert a force true or false?
Answer:
false
Explanation:
An electric field may do work on a charged particle, while a magnetic field does no work.
tion 7
In the beginning of the reaction, A B+C, 2 moles of A are taken, out of which 0.5 moles
gets dissociated. What is the amount of dissociation of A?
(1) 0.5
(2) 1
(3) 0.25
(4) 4.2
What is the molecular weight of magnesium chloride?
Answer:
Magnesium chloride/Molar mass
95.211 g/mol
Explanation:
What is it called when instead of getting rid of a product you find another
use for the product?
Answer:
Recycling.
Explanation:
When instead of getting rid of a product you find another use for the product, it is called recycling.
Recycling can be defined as a process which typically involves gathering, processing and transformation of materials or products that would otherwise be gotten rid of as waste materials or trash into new products that could be used for another purpose.
Basically, the recycling process involves turning a trash or unwanted product into a treasure (new product) that is capable of serving another purpose.
For example, the crown cork of a bottle could be gathered and processed into art forms that can be used for decorations.
Rocks are classified on the basis of
Answer:
Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. This transformation produces three general classes of rock: igneous, sedimentary and metamorphic. Those three classes are subdivided into many groups.
Explanation:
Jane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?
A. Marina
B. The family car
C.The library
D. Jane’s house
Answer:
B) The family car
Explanation:
I hope this helps :)
2. How many moles are there in 20 grams of Carbon?
Answer:
1.6666666666666 is the ans bcz in each mole there r 12 grams of carbon so the ans is goingtobe 20÷12
According to the mole concept, there are 1.66 moles in 20 grams of carbon.
What is a mole?
Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Number of moles is calculated as, mass/molar mass, thus on substitution , number of moles=20/12=1.66 moles.
Thus, there are 1.66 moles in 20 grams of carbon.
Learn more about moles,here:
https://brainly.com/question/26416088
#SPJ6
A sample of 0.600 mol of a metal M reacts completely with excess fluorine to form 46.8 g of MF2.?
a) How many moles of F are in the sample of MF2 that forms? (1.20 mol F)
b) How many grams of M are in this sample of MF2?
c) What element is represented by the symbol M? (Ca)
Answer:
See Explanation
Explanation:
Given:
moles M = 0.600 mole
moles F = excess (for rxn stoichiometry)
Formula Weight (F.Wt.) of F = 19 grams/mole (from Periodic Table)
Yield in grams = 46.8 grams (assuming theoritical yield)
Rxn: M + F₂ => MF₂
0.600mol Excess 0.600mol (1:1 rxn ratio for M:MF₂)
a. moles of F in MF₂ = 2(0.600) moles F = 1.2 moles F
b. mole weight MF₂ = 46.8g/0.600mol = 78g/mole
F.Wt. MF₂ = F.Wt. M + 2(F.Wt. F)
=> mass M = F.Wt. M = [F.Wt. MF₂ - 2(F.Wt. F)] = 78g/mol. - 2(19g/mol.)
= (78 - 38) grams/mole = 40 grams/mole
c. Calcium (Ca) has F.Wt. = 40 grams/mole (compared to Calcium on Periodic Table.
From the question, the metal is the limiting reactant and must be used to obtain the required results which are;
a) There are 1.20 mol F in MF2.
b) There are 40g of M in MF2.
c) M is calcium.
From the reaction equation;
M + F2 ----> MF2
Since the reaction is 1:1, 0.600 mol of MF2 is formed
Note that 1 mole of MF2 contains two moles of F and one mole of M
Hence, number of moles of F in MF2 = 2 * 0.600 mol = 1.20 mol F
Since 1 mole of M is contained in MF2, there are 0.600 moles of M in MF2.
If 1 mol of M forms 1 mole of MF2
And, 0.600 mol of M form 0.600 mol of MF2
Number of moles of MF2 = mass/molar mass
Number of moles of MF2 = 0.600 mol
Mass of MF2 formed = 46.8 g
Molar mass of MF2 = mass/Number of moles of MF2
Molar mass of MF2 = 46.8 g/0.600 mol
Molar mass of MF2 = 78 g/mol
Molar mass = Sum of Relative atomic mass of component atoms.
Hence;
78 = M + 2(19)
M = 78 - 2(19)
M = 40 g
The element must be calcium
Learn more: https://brainly.com/question/17275626
Answering the following questions will help you focus on the outcomes of the experiments.
Experiment 1:
1. What happens to the water in the small tube as the water in the test tube absorbs heat?
2. Why do you think a small tube was used to observe the expansion of water?
Experiment 2:
1. Compare the circumference of the balloon before and after freezing. What is the percent increase in this
measurement?
Combined Results
Write a summary paragraph discussing this experiment and the results. Use the following questions and topics to help
guide the content of your paragraph.
Summarize the conclusions that you can draw from this experiment. Use the questions above to guide your ideas.
2. Summarize any difficulties or problems you had in performing the experiment that might have affected the results.
Describe how you might change the procedure to avoid these problems.
3. Describe at least two real-world issues or examples that illustrate the findings of this experiment.
WRITER
Word Count: of 400
OVERALL SCORE:
Answer:
ex.1
1.The water in the test tube expands as it is heated. There is only one direction to expand in, the glass tube. This glass tube is narrow so that a small change in volume will result in a considerable change in height; your signal is amplified. This is the same phenomenon as in thermometers with a glass bulb on the lower end.
2. there will be a thermal expansion will happened.
Which of the following accurately represents the relationship between ceramic and
metal?
Relationship between metal and ceramic is accurately represented by the statement that metal is a better conductor than ceramics.
What are conductors?Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold. Substances which enable conduction are called conductors.Conductors allow passage heat and electricity through the material.
In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .
When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:
1) heat conduction
2) electrical conduction
3)sound conduction
Learn more about conductors,here:
https://brainly.com/question/8426444
#SPJ6
what’s the answer please
Answer:
5 × 10⁻³ mol
Explanation:
Step 1: Given data
Volume of HCl solution (V): 25 cm³Molar concetration of the HCl solution (C): 0.2 mol/dm³Step 2: Convert "V" to dm³
We will use the conversion factor 1 dm³ = 1000 cm³.
25 cm³ × 1 dm³/1000 cm³ = 0.025 dm³
Step 3: Calculate the moles of HCl (n)
We will use the definition of molarity.
C = n/V
n = C × V
n = 0.2 mol/dm³ × 0.025 dm³ = 5 × 10⁻³ mol
AlCl3(s)+Ca3N2(s)→AlN(s)+CaCl2(s)
Answer:
the subject of a talk, piece of writing, exhibition, etc.; a topic.
Explanation:
Answer:
1 NH4NO3(s) → 1 N2(g) + 4 H2O(g) + 2 O2(g)
Explanation:
A sample of NH3(g) is placed in a rigid container. When the equilibrium below is established, the partial pressure of hydrogen gas is 0.978 atm. What is the partial pressure of N2(g) at equilibrium?
Answer:
PpN₂ = 0.326 atm
Explanation:
In this case, let's write the equilibrium reaction taking place here:
2NH₃(g) <------> 3H₂(g) + N₂(g)
Now, we know that when the reaction reach the equilibrium the partial pressure of H₂ is 0.978 atm, so, let's write an ICE chart and see what's happening here:
2NH₃(g) <------> 3H₂(g) + N₂(g)
i) y 0 0
c) -2x +3x x
e) y-2x 3x x
At the beggining we just have the sample of NH₃, we don't know how much but we don't need that data to get the partial pressure. In equilibrium, its produced hydrogen and nitrogen, and we know how much of hydrogen was produced, so, with that we can solve for the value of the partial pressure of NO by a simple math operation:
PpH₂ = 0.978 atm = 3x
PpN₂ = x
PpN₂ = PpH₂ / 3
PpN₂ = 0.978 / 3
PpN₂ = 0.326 atmHope this helps
When drawing a Bohr model for Sulfur, how many energy levels will you
draw?
5
4
3
2.
Answer:
3
Explanation:
2,8,6
Move the red warning icon to focus of the earthquake.
Move the green location icon to the epicenter of the earthquake.
Move the blue star icon to the fault.
Answer:
Red goes in the spiky yellow box. Green goes where the red circles are. Blue goes in the small yellow box that is pointing to the line.
Explanation:
The focus of an earthquake is where it starts in the earth. The epicenter is the part directly above the focus on the surface. The fault is the part where the earth's crust splits.
Which food dyes in the diagram on the right only contain one colour?
( Science, Chromatography )