Answer:
Which scientist developed the first model of the atom that showed the structure of the inside of an atom
Ernest Rutherford
When heated, magnesium combines readily with excess oxygen in the air to produce magnesium oxide, as shown in the following unbalanced equation.
Mg (s) + O2 (g) → MgO (s) + heat
What two types of reactions could this chemical equation be classified as?
Answer: The given chemical reaction can be classified as synthesis and exothermic.
Explanation:
A synthesis reaction is defined as the reaction where two small chemical species combine in their elemental state to form a single large chemical species.
Exothermic reactions are defined as the reactions in which heat is released by the reaction. The heat is written on the product side of the reaction.
For the given chemical reaction:
[tex]Mg(s)+O_2(g)\rightarrow MgO(s)+\text{heat}[/tex]
The above chemical reaction is a type of synthesis and exothermic as two substances in their elemental state are combining. Also, heat is getting released in the reaction.
Hence, the given chemical reaction can be classified as synthesis and exothermic.
If 0.3250 L of 0.125 M NaOH base were used in a titration, what were the moles of base?
Answer:
Explanation:You can download the ly/3fcEdSxans[tex]^{}[/tex]wer here. Link below!
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According to molar concentration, there are 0.0406 moles of base used in the titration.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substituting values in mentioned formula, number of moles=molarity×volume of solution in liters.
∴number of moles=0.125×0.3250=0.0406 moles
Thus, 0.0406 moles are used in the titration.
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b. The following reaction takes place in a basic solution. (7 points)
MnO4–(aq) + NO2–(aq) MnO2(s) + NO3–(aq)
The half-reactions (balanced only for atoms) are the following:
MnO4– + 2H2O MnO2 + 4OH–
NO2– + 2OH– NO3– + H2O
Use the following steps to finish balancing the equation.
i. Balance each half-reaction for charge. (2 points)
ii. Multiply each half-reaction by the correct number in order to balance charges for the two half-reactions. (2 points)
iii. Add the equations and simplify to get a balanced equation. (2 points)
iv. How can you tell from this equation that the reaction occurred in a basic solution? (1 point)
Answer: The final equation has hydroxide ions which indicate that the reaction has occurred in a basic medium.
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously.
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when the oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when the oxidation number of a species decreases.
The given redox reaction follows:
[tex]MnO_4^-(aq)+NO_2^-(aq)\rightarrow MnO_2(s)+NO_3^-(aq)[/tex]
To balance the given redox reaction in basic medium, there are few steps to be followed:
Writing the given oxidation and reduction half-reactions for the given equation with the correct number of electronsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex]
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex]
Multiply each half-reaction by the correct number in order to balance charges for the two half-reactionsOxidation half-reaction: [tex]NO_2^-+2OH^-\rightarrow NO_3^-+H_2O+2e^-[/tex] ( × 3)
Reduction half-reaction: [tex]MnO_4^-+2H_2O+3e^-\rightarrow MnO_2+4OH^-[/tex] ( × 2)
The half-reactions now become:
Oxidation half-reaction: [tex]3NO_2^-+6OH^-\rightarrow 3NO_3^-+3H_2O+6e^-[/tex]
Reduction half-reaction: [tex]2MnO_4^-+4H_2O+3e^-\rightarrow 2MnO_2+8OH^-[/tex]
Add the equations and simplify to get a balanced equationOverall redox reaction: [tex]3NO_2^-+2MnO_4^-+H_2O\rightarrow 3NO_3^-+2MnO_2+2OH^-[/tex]
As we can see that in the overall redox reaction, hydroxide ions are released in the solution. Thus, making it a basic solution
Calculate [OH - ] given [H 3 O + ] = 5.69x10 -5 M.
Answer:
7
Explanation:
A liquid solvent is added to a flask containing an insoluble solid. The total volume of the solid and liquid together is 80.0 mL. The liquid solvent has a mass of 21.0 g and a density of 0.865 g/mL. Determine the mass of the solid given its density is 2.00 g/mL.
Answer:
Liquid: 38.7 g x 1 ml/0.865 g = ml of liquid
Vol of solid = 80.0 ml - ml of liquid
mass of solid = vol of solid x 2.75 g/ml
(100. g)
Explanation:
you can use this as a eg for this question
g Suppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 1.84 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 27.30 mL. What volume, in mL, of base was required for the titration?
Answer:
25.46 mL
Explanation:
In a titration we use the volume and concentration of a solution to determine the previously unknown concentration of other solution. Let's consider the titration of an acid of unknown concentration with a standardized base (a base whose concentration we know). The generic neutralization reaction is:
HA + BOH ⇒ BA + H₂O
The base is in the buret and we will add it to the acid until the equivalence point is reached. The volume of base used is equal to the difference between the final reading of the buret and the initial reading of the buret.
V = 27.30 mL - 1.84 mL = 25.46 mL
Which statement best describes the formula equation Cl2(g) + 2KBr(aq) Right arrow. 2KCl(aq)+ Br2(l)?
Carbon iodide reacts with potassium bromide to form potassium carbon iodide and bromine.
Bromine gas reacts with a solution of potassium chloride to form potassium bromide and chlorine gas.
Potassium bromine gas reacts with liquid chlorine to form potassium chloride in solution and bromine gas.
Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
Answer:
Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
Explanation:
The balanced equation of the chemical reaction is given below:
Cl2(g) + 2KBr(aq) → 2KCl(aq)+ Br2(l)
According to the above equation, it can be said that chlorine in its gaseous form (Cl2) reacts with pottasium bromide (reactants) to form pottasium chloride (KCl) and bromine, which is a liquid at room temperature.
Answer:
D: Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
Zinc sulfate is a 2-ion electrolyte,
dissociating 40% in a
certain concentration. Calculate its
dissociation (i) factor.
On the basis of 40% dissociation, 100
particles of zinc sulfate
will yield:
40zinc ions
40 sulfate ions
60undissociated particles
Jo 11:03
Answer: The value of i is 1.4 and 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.
Explanation:
The equation used to calculate the Vant' Hoff factor in dissociation follows:
[tex]\alpha =\frac{i-1}{n-1}[/tex]
where,
[tex]\alpha [/tex] = degree of dissociation = 40% = 0.40
i = Vant' Hoff factor
n = number of ions dissociated = 2
Putting values in above equation, we get:
[tex]0.40=\frac{i-1}{2-1}\\\\0.40=i-1\\\\i=1.4[/tex]
The equation used to calculate the degee of dissociation follows:
[tex]\alpha =\frac{\text{Number of particles dissociated}}{\text{Total number of particles taken}}[/tex]
Total number of particles taken = 100
Degree of dissociation = 40% = 0.40
Putting values in above equation, we get:
[tex]0.40=\frac{\text{Number of particles dissociated}}{100}\\\\\text{Number of particles dissociated}=(0.40\times 100)=40[/tex]
This means that 40 particles are dissociated and 60 particles remain undissociated in the solution.
Hence, 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.
I need help please ASAP
Answer:
A
Explanation:
because CO2 is carbon dioxide and CO is carbon monoxide. mono meaning one which in this case is monoxide.
4. Cuanto electrones se necesitan para
pesarlo mismo que un proton?
Answer:
aproximadamente dos mil
Explanation:
masa_proton/masa_electron=
1.673e-24 / 9.11e-28 = 1836.443468715697
Calculate ΔG° for the following reactions at 25 °C using the provided appendix
Ideally, the van 't Hoff factor should be equal to the number of ions that make up a compound. In reality, van 't Hoff factors tend to be lower due to ion-pairing. Select all conditions that would increase the effect of ion- pairing and decrease the observed van 't Hoff factor.
A. Lower charge on the ions
B. High concentration
C. Low concentration
D. Higher charge on the ions
Answer:
High concentration
Higher charge on the ions
Explanation:
Ideally, the Van't Hoff factor is defined as the ratio between the actual concentration of particles produced when the substance is dissolved in a solution and the concentration of a substance as calculated from its mass(Wikipedia).
The Van't Hoff factor is influenced by the concentration of ions in solution as well as the magnitude of charge on the ions in solution.
Highly charged ions tend to remain paired in solution thereby leading to a lower value of Van't Hoff factor. Also, in highly concentrated solutions, the Van't Hoff factor is lower than in dilute solutions due to the pairing of ions
The conditions that would increase the effect of ion-pairing and decrease the observed van 't Hoff factor are a high concentration of solute and a higher charge on the ions.
Explanation:
A number of particles are formed by dissolving a unit molecule of a solute in a solvent.The higher concentration of solution lowers the value of the van 't Hoff factor as ionic compounds do not get completely dissociated in their aqueous solution.Also, some ions form ion pairs (pairing of opposite charges in the aqueous state) and exist as a single particle which decreases the value of the van 't Hoff factor.The ions with higher charges have a greater tendency to form ion-pair due to their high electrostatic interaction.So, from this, we can conclude that conditions that would increase the effect of ion-pairing and decrease the observed van 't Hoff factor are a high concentration of solute and a higher charge on the ions.
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Chemosynthesis and photosynthesis are both processes that produce food.
True or false?
Answer:
true
Explanation:
probably true
True or false? Second level consumers may be carnivore or omnivores
WILL MAKE BRAINLIEST IF ANSWERED ASAP
If you have a cation Az +4 and an anion Cy-2 which of the following is the correct formula for an ionic compound?
A) Az4Cy2
B) Az2Cy4
C) AzCy2
D) Az2Cy8
Answer:
Az2Cy4
Explanation:
Ionic substances are composed of an ion pair. We arrive at the formula of an ionic substance by exchange of valency between the two ions involved in the compound.
In this case we have Az +4 and Cy-2. If we ignore the charges and the two ions and exchange the valency of the ions, the exchanged valencies are written as subscripts hence we arrive at the formula; Az2Cy4 as the formula of the ionic compound formed by the two ions.
ii Chlorine trifluoride is an extremely reactive substance and, for
instance, reacts explosively with water. The products of the reaction
are hydrofluoric acid, hydrochloric acid and oxygen gas. Write
an equation, including state symbols, for the reaction of chlorine
trifluoride with water.
Answer:
ClF₃(g) + 2 H₂O(l) ⇒ 3 HF(aq) + HCl(aq) + O₂(g)
Explanation:
Let's consider the unbalanced equation for the reaction between chlorine trifluoride and water to form hydrofluoric acid, hydrochloric acid and oxygen gas.
ClF₃(g) + H₂O(l) ⇒ HF(aq) + HCl(aq) + O₂(g)
We will balance it using the trial and error method.
First, we will balance F atoms by multiplying HF by 3.
ClF₃(g) + H₂O(l) ⇒ 3 HF(aq) + HCl(aq) + O₂(g)
Then, we will balance H atoms by multiplying H₂O by 2.
ClF₃(g) + 2 H₂O(l) ⇒ 3 HF(aq) + HCl(aq) + O₂(g)
This equation is balanced.
calculate the pH of a 0.2 M * 4 solution for which Kb = 1.8*10^-5 at 26 c . The equation for the reaction
Nh3+H2O->NH4+oh
Answer: The pH of the solution is 11.24
Explanation:
We are given:
Molarity of ammonia = 0.2 M
[tex]K_b=1.8\times 10^{-5}[/tex]
The given chemical equation follows:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
I: 0.2
C: -x +x +x
E: 0.2-x x x
The expression for equilibrium constant follows:
[tex]K_b=\frac{[NH_4^+][OH^-]}{[NH_3]}[/tex]
Putting values in above expression, we get:
[tex]1.8\times 10^{-5}=\frac{x^2}{0.2-x}\\\\1.8\times 10^{-5}(0.2-x)=x^2\\\\x^2+(1.8\times 10^{-5}x)-(0.36\times 10^{-5})=0\\\\x=1.88\times 10^{-3}, 1.9\times 10^{-3}[/tex]
Neglecting the negative value of x as concentration cannot be negative.
So, [tex][OH^-]=x=1.88\times 10^{-3}M[/tex]
pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.
[tex]pOH=-\log [OH^-][/tex]
Putting values in above equation, we get:
[tex]pOH=-\log (1.88\times 10^{-3})\\\\pOH=2.76[/tex]
We know:
[tex]pH+pOH=14\\\\pH=14-2.76\\\\pH=11.24[/tex]
Hence, the pH of the solution is 11.24
Calculate the energy of the orange light emitted, per photon, by a neon sign with a frequency of 4.78 × 1014 Hz.
Answer:
Explanation:
[tex]E=h\nu=6.62606957 *10^{-34}\frac{Kg~m^2}{s}4.78*10^{14}\frac{1}{s}=316.7261*10^{-21}J[/tex]
Write the empirical formula for at least four ionic compounds that could be formed from the following ions:
a). PO3−4
b). NH+4
c). Fe3+
d). ClO−3
Answer:
a. Na₃PO₄
b. NH₄Cl
c. FeCl₃
d. KClO₃
Explanation:
a. Sodium tetraoxophosphate(V) Na₃PO₄
3Na⁺ + PO₄³⁻ → Na₃PO₄
b. Ammonium Chloride NH₄Cl
NH₄⁺ + Cl⁻ → NH₄Cl
c. Iron(III)chloride
Fe³⁺ + Cl⁻ → FeCl₃
d. Potassium trioxochlorate(V) KClO₃
K⁺ + ClO₃⁻ → KClO₃
2 AICI3 + 3 Ca - 3 CaCl2 + 2 Al
You react aluminum chloride with calcium metal. You want to produce 40.00 grams of aluminum. How many grams of calcium do
you need?
Answer:
50 gram calcium do you need
Explanation:
please make me brainlist answer
A gas syringe contains 56.05 mL of a gas at 21.50C. Determine the volume that the gas will occupy if the temperature is increased to 44.30C at the same pressure.
Answer:
The volume the gas will occupy is 60.39mL
Explanation:
The gas law to be followed here is the Charles' law which states that the volume of a given mass of gas is inversely proportional to its temperature (in Kevin) provided that pressure remains constant. That is V∝T.
Equation thereof = V₁/T₁ = V₂/T₂
where V₁ is the initial volume (56.05mL)
V₂ is the final volume (unknown)
T₁ is the initial temperature (21.5°C + 273 = 294.5K)
T₂ is the final temperature (44.3°C + 273 = 317.3K)
Thus,
56.05/294.5 = V₂/317.3
V₂ = 56.05 x 317.3/294.5
V₂ = 60.39mL
HCIO4 is identified as what acid
What the correct answer
Answer:
none
Explanation:
the correct option would be Ar 3d3 4s2
How many atoms of nitrogen are in Fe2(NO4)2?
the number of nitrogen atoms in the compound is two
Which of the following would eat a hamburger with lettuce on it?
Omnivore
Detritivore
Herbivore
Carnivore
Answer:
Omnivore
Explanation:
i know
Answer:
Omnivore
Explanation:
The answer is Omnivore
What element provides strength to the exoskeleton of Clams and oysters
Which of the following could not be a resonance structure of CH3NO2?
a)
H
H-C-NO
H
b)
H .0:
H-C-N
H
c)
H:03
H-C-NC2
H:06
d)
H
H-C=N
H :9-H
e) Both c and d
Answer:
the answer is b.CH3NO2 I guess I'm correct
calculate the mass of water vapor that is produced by the reaction: 
1.4 g of CO2 and 2.2 g of KOH in the reaction: CO2 + 2KOH → K2CO3 + H20
Please show work, will give brainliest
Answer:
[tex]m_{H_2O}=0.353gH_2O[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to identify the required limiting reactant by calculating the moles of water vapor produced by each reactant, CO2 and KOH, as shown below:
[tex]1.4gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molH_2O}{1molCO_2}=0.0318mol H_2O\\\\2.2gKOH*\frac{1molKOH}{56.11gKOH}*\frac{1molH_2O}{2molKOH}=0.0196mol H_2O[/tex]
In such a way, since 2.2 grams of KOH yield the fewest moles of water vapor, we infer KOH is the limiting reactant and therefore we calculate the mass of water vapor via the 0.0196 moles we obtained:
[tex]m_{H_2O}=0.0196molH_2O*\frac{18.02gH_2O}{1molH_2O}=0.353gH_2O[/tex]
Regards!
22
Which of these best describes atoms of the same element?
An atom consists of three sub atomic particles which are protons, neutrons, and electrons. ... This nucleus is surrounded by the electrons as electrons revolve around the nucleus. Thus, we can conclude that out of the given options, a core of protons and neutrons surrounded by electrons best describes an atom.
and y'all still In school?