Ammonia burns in the presence of a copper catalyst to form nitrogen gas. 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) ΔΗ = -1267 kJ What is the enthalpy change to burn 38.4 g of ammonia?
Answer:
-713 kJ
Explanation:
Step 1: Write the balaned thermochemical equation
4 NH₃(g) + 3 O₂(g) → 2 N₂(g) + 6 H₂O(g) ΔΗ = -1267 kJ
Step 2: Calculate the moles corresponding to 38.4 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
38.4 g × 1 mol/17.03 g = 2.25 mol
Step 3: Calculate the enthalpy change to burn 2.25 mol of ammonia
According to the thermochemical equation, 1267 kJ are released per 4 moles of ammonia that react.
2.25 mol × (-1267 kJ/4 mol) = -713 kJ
Studying and got stuck if someone can help me.
Answer:
Ph level 0-7 is a acid
ph level 7-14 is base
bases turn paper blue
acids dissolve metal
acids contain hydrogen ions
Explanation:
I dont know the last one all I know that they become neutral when acids and bases are mixed.
What is the pH of a solution whose hydronium ion [H20+] (or proton [H+1)
concentration is 7.6' 10-5 M?
Answer:
[tex]pH = - log(7.6 \times {10}^{ - 5} ) \\ pH = 4.12[/tex]
What is the mass of 6 atom(s) of copper in grams?
Answer:
6.33×10¯²² g
Explanation:
From the question given above, the following data were obtained:
Number of atoms = 6 atoms
Mass of copper (Cu) =?
From Avogadro's hypothesis, we understood that:
6.02×10²³ atoms = 1 mole of Cu
But 1 mole of Cu = 63.5 g
Thus,
6.02×10²³ atoms = 63.5 g of Cu
Finally, we shall determine the mass of 6 atoms of copper. This can be obtained as illustrated below:
6.02×10²³ atoms = 63.5 g of Cu
Therefore,
6 atoms = (6 × 63.5) / 6.02×10²³
6 atoms = 6.33×10¯²² g of Cu
Therefore, the mass of 6 atoms of copper is 6.33×10¯²² g.
An ion has 38 protons, 36 electrons, and 40 neutrons, what us the elements symbol
The symbol of the element in which it's ion has 38 protons, 36 electrons, and 40 neutrons is ⁷⁸₃₈Sr
How do I determine the symbol of the element?To obtain the symbol of the element, we shall obtain the mass number of the element. This is shown below:
Proton = 38Neutron = 40Mass number = ?Mass number = Proton + Neutron
Mass number = 38 + 40
Mass number = 78
Finally, we shall determine the symbol of the element. Details below:
Proton = 38Atomic number (z) = Proton = 38Mass number (A) = 78Symol of element =?From the periodic table, the element with atomic number of 38 is Strontium.
Thus, the symbol of the element will be ⁷⁸₃₈Sr
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A hard-water solution contains 4.8 g of calcium chloride. How much sodium phosphate in grams should be added to the solution to completely precipitate all of the calcium
Answer:
4.7 g
Explanation:
The reaction that takes place is:
3CaCl₂(aq) + 2Na₃PO₄(aq) → Ca₃(PO₄)₂(s) + 6NaCl(aq)First we convert 4.8 g of CaCl₂ into moles, using its molar mass:
4.8 g ÷ 110.98 g/mol = 0.0432 mol CaCl₂Then we convert CaCl₂ moles into Na₃PO₄ moles, using the stochiometric coefficients of the balanced reaction:
0.0432 mol CaCl₂ * [tex]\frac{2molNa_3PO_4}{3molCaCl_2}[/tex] = 0.0288 mol Na₃PO₄Finally we convert 0.0288 moles of Na₃PO₄ into grams, using its molar mass:
0.0288 mol Na₃PO₄ * 164 g/mol = 4.7 gWhich of the following is formed last in daughter cells when plant cells divide?
The nucleus
The nuclear envelope
The cell membrane
The cell wall
Answer:
The Cell Wall
Explanation:
Naturally occurring gallium is a mixture of isotopes
that contains 90.11% of Ga-69 (atomic mass = 68.93
u) and 9.89% of Ga-71 (atomic mass 70.92 u).
What is the average atomic mass of naturally
occurring gallium?
A) 69.93 amu
C) 69.50 amu
B) 69.12 amu
D) 69.00 amu
The average potential energy of water molecules is greatest in
The average potential energy of water molecules is greatest in in steam at 100 °C. Potential energy is indeed a characteristic of a system.
What is potential energy?Potential energy is stored energy that is affected by the relative location of various components in a system. When a spring is squeezed or extended, its potential energy increases.
Potential energy is indeed a characteristic of a system, not an individual substance or particle; for example, the system made of Earth and the elevated ball has greater potential energy as even the two are separated. Potential energy exists in systems having pieces that exert forces on one another of varying magnitudes based on their configuration, or relative location. The average potential energy of water molecules is greatest in steam at 100 °C.
Therefore, the average potential energy of water molecules is greatest in steam at 100 °C.
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Help guys please question 3 in picture ASAP pls
Answer:
1 Spinal fluid
2 Milk
3 Saliva
4 Urine
5 Gastric content
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary for us to calculate the pH of both gastric content and spinal fluid by using the following equations and works:
[tex]pH_{gastric}=-log(10^{-2})=2.0\\\\pH_{spinal}=14+log(10^{-6.6})=7.4[/tex]
Thus, we rank them as follows:
1 Spinal fluid
2 Milk
3 Saliva
4 Urine
5 Gastric content
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The density of water is about 1.0 g/mL at room temperature. Briefly explain how the density of an aqueous solution at room temperature can be significantly less than 1.0 g/mL. Give an example of such a solution.
Answer:
The density of water is about 1.0 g/mL at room temperature.
Briefly explain how the density of an aqueous solution at room temperature can be significantly less than 1.0 g/mL.
Give an example of such a solution.
Explanation:
That means 1.0mL of water weighs ---- 1.0g
If any other aqueous solution which has mass less than 1.0g will have density less than 1.0g.
For example aqueous solution of sulfuric acid has density 0.98g/mL.
That means 1mL of sulfuric acid has mass 0.98g.
Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water, for example, sulfuric acid which has a density 0.98g/mL.
What is density of a substance?The density of a substance is the ratio of the mass to the volume of that substance.
Density measures compactness.
More compact substances are more dense.
The density of water is about 1.0 g/mL at room temperature.
This means that 1.0mL of water weighs 1.0g
1.0 mL of an aqueous solution whose mass is less than 1.0g will have density less than that of water.
Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water.
An example of an aqueous solution whose density is less than that of water is sulfuric acid which has a density 0.98g/mL.
Sulfuric acid is prepared by dissolving sulphur (vi) oxide, a gas, in water.
This means 1mL of sulfuric acid has mass 0.98g.
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An eccentric chemistry professor (not mentioning any names) stops in every day and orders 200ml of Sumatran coffee at precisely 75.0°C. You then need to add enough milk at 5.00°C to drop the temperature of the coffee, initially at 95.0°C, to the ordered temperature.
Answer:
68.97g of milk must be added
Explanation:
To solve this problem we need to use the equation:
Q = C*m*ΔT -Coffee cup calorimeter equation-
This equation relates mass and change in temperature with heat of solution, Q.
The energy that decreases in the milk is the same that increases in the milk. That is:
Q(milk) = Q(tea)
Using the equation:
4.184J/molK* Mass milk * (65.0°C - 7.00°C) = 4.184J /molK * 200g (Tea) * (85.0°C - 65.0°C)
Mass milk * 58.0°C = 200g * 20.0°C
Mass milk = 4000g°C / 58.0°C
Mass milk =
68.97g of milk must be added
What three parts of your eye work together to create a clear image?
Answer:
cornea,Jens and pupil
tma Po yan
Give the change in conditions required to go from a gas to a solid. Give the change in conditions required to go from a gas to a solid. Decrease temperature or reduce pressure. Increase temperature or reduce pressure. Increase temperature or increase pressure. Decrease temperature or increase pressure. None of the above.
Answer:
Decrease temperature or reduce pressure
The mass percent of element X
in X(NO3)2 is 52.55%.
Chemical analysis of a pure
sample of X(NO3)2 shows that
it contains 67.50 g of element
X. What is the total mass of
the pure sample?
Answer:
128.4 g
Explanation:
Step 1: Given data
Mass percent of element X in X(NO₃)₂: 52.55%Mass of the element X in the sample: 67.50 gStep 2: Determine the total mass of the sample
The mass percent of element X in X(NO₃)₂ is 52.55%, that is, there are 52.55 g of X every 100 g of X(NO₃)₂. Then, the mass of X(NO₃)₂ that contains 67.50 g of X is:
67.50 g X × 100 g X(NO₃)₂/52.55 g X = 128.4 g X(NO₃)₂
which of the following experiments raises ethical concerns
Answer:
Research that releases a poisonous gas into the air.
Explanation:
Since I don't know the options I will guess it is ^
Write the equation showing the formation of a monosubstituted product when butane reacts with chlorine. Use molecular formulas for the organic compounds (C before H, halogen last) and the smallest possible integer coefficients.
Answer:
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
Explanation:
Alkanes react with halogens in the presence of light to yield alkyl halides. The degree of substitution increases as the reaction progresses. The reaction occurs by free radical mechanism.
The reaction between butane and chlorine molecule to yields a monosubstitution product occurs as follows;
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
Washes and extractions are both techniques that use a separatory funnel to separate liquid layers. However, washes and extractions have differences. Determine whether each statement applies to washes or extractions.
Leaves impurities in their starting layer Choose...
Moves impurities from one layer to another Choose...
Moves desired compound from one layer to another Choose...
Often involves a reaction in one of the layers Choose...
Leaves desired compound in its starting layer Choose...
Answer:
Leaves impurities in their starting layer - Extraction Moves impurities from one layer to another - Wash Moves desired compound from one layer to another - Extraction Often involves a reaction in one of the layers - Extraction Leaves desired compound in its starting layer - WashExplanation:
Both extraction and wash are technical materials separation processes. Both seek to carry out a separation of liquid-liquid, through the relationship between solvent and solute present in this solution. Both use a separation funnel and are very similar processes where the main difference is the purpose that each one seeks to exercise. The extraction causes the dissolution of the material that the researcher wants to leave behind. this process leaves impurities in the initial solution layer and moves the researcher's desired compound to the second layer of solution. A chemical reaction can take place during this process.
A wash, on the other hand, dissolves all impurities from the solution and extracts the compound desired by the researcher. Therefore, we can conclude that during this process the impurities are moved from one layer to another in the solution until it is discarded from the funnel, leaving the desired compound in the initial layer.
Verdadero o falso si un átomo presenta de 5 a 7 electrones en su nivel más extremo tenderá a perderlos?
How many grams of hydrogen gas, H, are necessary to produce 119.0 g of ammonia, NH3?
Answer:
What's the equation?
Answer:
14.5 g
Explanation:
its true
The diagram shows an experiment. damp litmus paper gas given off mixture of ammonium chloride and sodium hydroxide 1 heat What is the name of the gas and the final colour of the litmus paper? gas colour A ammonia blue B ammonia red с chlorine white D chlorine red plz guys help me
Answer:
The correct answer is - A. ammonia blue.
Explanation:
It is given that there is a mixture of ammonium chloride and sodium hydroxide and if we heat the Mixture of NH4Cl and NaOH then, the following reaction will take place-
NH4Cl (aq)+ NaOH (aq)==> NaCl (aq) + NH3 (g)+ H2O (l)
In this reaction, there is a release of NH3 gas which is absorbed on litmus paper. We know that NH3 gas is basic in nature and so it will turn litmus paper blue.
Thus, the correct answer would be - NH3 (ammonia ) and Blue
how to solve the chemical formula for Calcium Chlorate
Answer:
Ca(ClO3)2
Explanation:
The chemical formula of calcium chlorate is Ca(ClO3)2, which means in this molecule, Ca2+ ion is bonded to two ClO3- ions. So the formula can be expended to O3Cl-Ca-ClO3, or CaCl2O6 (basically times the numbers of the elements inside the bracket by the number outside the bracket.
You are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the ee of this solution
Answer:
ee = 96%
Explanation:
Enantiomeric excess, ee, is a way to express a mixture that is not enantiomerically pure. It is defined as 100 times the ratio between the differences of amounts of enantiomers and the total amunt. that is:
ee = |A-B|/ A+B * 100
ee = |98%-2%| / 98+2 * 100
ee = 96%A concentration cell is constructed by using the same half-reaction for both the cathode and anode. What is the value of standard cell potential, for a concentration cell that combines a silver anode in contact with 0.10 M silver nitrate and a silver cathode in contact with 0.00003 M silver nitrate
Solution :
A cell that is concentrated is constructed by the same half reaction for the anode as well as he cathode.
We know,
In a standard cell,
the reduction half cell reaction is :
[tex]$Ag^+(aq)+e^- \rightarrow Ag(s) E^0 = -0.80 \ V$[/tex]
The oxidation half ell reaction :
[tex]$Ag(s) \rightarrow Ag^+(aq) + e^- \ E^0= +0.80 \ V$[/tex]
Thus the complete reaction of the cell is :
[tex]$Ag^+(aq)+ Ag(s) \rightarrow Ag^+(aq)+Ag(s)$[/tex]
[tex]$E^0 $[/tex] cell = [tex]$E_R - E_L = 0.00 \ \text{volts}$[/tex]
Why does glucose and acentic acid have the same empirical formula
Answer:
Examples. Glucose (C6H12O6), ribose (C5H10O5), Acetic acid (C2H4O2), and formaldehyde (CH2O) all have different molecular formulas but the same empirical formula: CH2O.
Explanation:In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound.
Chromium (VI) forms two different oxyanions, the orange dichromate ion, Cr2o72-, And the yellow chromate ion, CrO4 2-. The equilibrium reaction between the ions is:
Cr2O7 2- (aq) + H2O(l)→ 2CrO4 2-(aq) + 2H(aq)
Explain
a) Why does the orange dichromate solution turn yellow when sodium hydroxide is added. Write the net ionic equation for this shift.
b) How will this system shift at equilibrium if the temperature is increased
Answer:
See explanation
Explanation:
Let us look at the reaction again;
Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)
When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).
The net ionic equation is;
OH^-(aq) + H^+(aq) ----> H2O(l)
The reaction;
OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.
Phenols do not exhibit the same pka values as other alcohols; they are generally more acidic. Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane
Answer:
Phenols do not exhibit the same pka values as other alcohols;
They are generally more acidic.
Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane.
Explanation:
According to Bromsted=Lowry acid-base theory,
an acid is a substance that can release [tex]H^{+}[/tex] ions when dissolved in water.
So, acid is a proton donor.
If the conjugate base of an acid is more stable then, that acid is a strong acid.
In the case of phenol,
the phenoxide ion formed is stabilized by resonance.
[tex]C_6H_5OH -> C_6H_5O^- +H^+[/tex]
The resonance in phenoxide ion is shown below:
Whereas in the case of cyclohexanol resonance is not possible.
So, cyclohexanol is a weak acid compared to phenol.
Question 8 of 24
Which statement best describes the intermolecular forces between H2 molecules and H2O molecules in the gas phase?
A. There is hydrogen bonding between H2 molecules and between H2O molecules.
B. There are no forces between H2 molecules or between H20 molecules.
C. There are no forces between H, molecules, and there is hydrogen bonding between the H20 molecules.
D. There are Van der Waals forces between both molecules and dipole-dipole forces between the water molecules.
help pleaseeee!!!!!
Answer:
it will be no. A that is thereis hydrogen bonding H2 molecules and between H2O molecules
Before the lab student needs to make necessary chemical reagent solutions, the teacher asked them to make 50.0mL of 1.0 M H2SO4 from a 6.0 M sock
V1=
M1=
V2=
M2=
Answer:
V1 = 8.3 mL
Explanation:
Step 1: Given data
Initial volume (V1): ?
Initial concentration (M1): 6.0 M
Final volume (V2): 50.0 mL
Final concentration (M2): 1.0 M
Step 2: Calculate the volume of the initial solution
We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the initial solution using the dilution rule.
M1 × V1 = M2 × V2
V1 = M2 × V2 / M1
V1 = 1.0 M × 50.0 mL / 6.0 M = 8.3 mL
We will take 8.3 mL of the 6.0 M solution and add water until we have 50.0 mL.
If you knew the volume of the solution containing NaCl(aq), determine how you would predict the mass of AlCl3(s) formed
Answer:
See explanation.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to realize that the NaCl solution must react with an aluminum-containing substance, say the hydroxide or any other salt, so that the following equation will take place:
[tex]3NaCl(aq)+Al^{3+}\rightarrow 3Na^+(aq)+AlCl_3(s)[/tex]
In such a way, given the volume of the NaCl solution, it must be necessary to know its concentration, in order to get moles of this salt, further use the 3:1 mole ratio of NaCl to AlCl3 and the molar mass of the latter (133.34 g/mol) in order to solve an stoichiometric setup like the following:
[tex]m_{AlCl_3}=V_{NaCl}*M_{NaCl}*\frac{1molAlCl_3}{3molNaCl} *\frac{133.34gAlCl_3}{1molAlCl_3}[/tex]
Besides, you must make sure the volume is in liters.
Best regards!
