Answer:
The 40 represents the atomic number and the number of proton in Zirconium. The "Zr" on the tile is the symbol of the elementp
I need help with my math but you can only choose one correct answer
Answer:
Explanation:
Decomposition is the answer.
If a compound breaks into two or more parts then it is called decomposition.
In the ground state, the valence electrons of a krypton atom are found in
1. The first shell
2. The outermost shell
3. Both the nucleus and the first shell
4. Both the first shell and the outermost shell
Answer: 2. The outermost shell
Explanation:
In an elements ground state, its electrons have the least amount of energy that they could have so they stay in their shells. When Krypton is in this state therefore, its valence electrons will stay in the outermost shell.
As Krypton has a total of 36 electrons in this state, there will be 8 valence electrons and they will all be in the outer shell.
A gas at STP occupies 0.055 L of space. If the pressure changes to
2.8 atm and the temperature increases to 195°C, what is the new
volume?
Answer:
0.034 L
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 0.055 L
Initial pressure (P₁) = stp = 1 atm
Initial temperature (T₁) = stp = 273 K
Final pressure (P₂) = 2.8 atm
Final temperature (T₂) = 195 °C = 195 °C + 273 = 468 K
Final volume (V₂) =?
The final volume of the gas can be obtained as follow:
P₁V₁ / T₁ = P₂V₂ / T₂
1 × 0.055 / 273 = 2.8 × V₂ / 468
0.055 / 273 = 2.8 × V₂ / 468
Cross multiply
273 × 2.8 × V₂ = 0.055 × 468
764.4 × V₂ = 25.74
Divide both side by 764.4
V₂ = 25.74 / 764.4
V₂ = 0.034 L
Therefore, the new volume of the gas is 0.034 L.
need it asap please!!
If a 30.0 mL of a 0.20 mol/L HOCN is titrated with 0.250 mol/L KOH,
What is the pH of the solution if 10.0 mL KOH is added?
Answer:
[tex]1 \: l \: contains \: 0.20 \: moles \: of \: HOCN \\ 0.03 \: l \: will \: contain \: (0.03 \times 0.20) \: moles \\ = 0.006 \: moles \: of \: HOCN \\ 1 \: l \: contains \: 0.250 \: moles \: of \: potassium \: hydroxide \\ 0.01 \: l \: will \: contain \: (0.01 \times 0.250) \\ = 0.0025 \: moles \: of \: potassium \: hydroxide \\ KOH + HOCN → KCN + H _{2}O \\ k _{b} = \frac{[K {}^{ + } ][OH {}^{ - } ]}{[KOH]} \\ moles \: of \: OH {}^{ - } \: remaining = 0.006 - 0.0025 \\ = 0.0035 \: moles \\ total \: volume = 0.03 + 0.01 \\ = 0.04 \: litres \\ 0.04 \: l \: contains \: 0.0035 \: moles \\ 1 \: l \: will \: contain \: ( \frac{1 \times 0.0035}{0.04} ) \\ = 0.0875 \: mol \: per \: litre \\ [H {}^{ + } ] = \frac{kw}{[OH {}^{ - } ]} \\ = \frac{1 \times {10}^{ - 14} }{0.0875} \\ = 1.143 \times {10}^{ - 13} \\ pH = - log(1.143 \times {10}^{ - 13} ) \\ pH = 12.94[/tex]
In the graphic,
X represents which element?
40
20
40x
20
Calcium
Ca
40
Zirconium
60
Neodymium
Nd
Zr
ins1502 assignment 03
Answer:
I think you forgot to post the question or picture
Please someone help me!
I need this done ASAP *URGENT*
I Need this done before Thursday or Friday because Friday is my last day of school so please finish this today!
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What’s the difference worksheet
Atoms,molecules,elements and compounds
PLEASE PLEASE PLEASE PLEASE PLEASEEEEEEE ANSWER THIS I only have TWO days of school left! And I need this done quickly
To solve this we must be knowing each and every concept related to chemical formula. Therefore, in the above given ways the chemical formula for the molecule can be written.
What is chemical formula?A chemical formula is a scientific notation that uses atomic symbol and numerical subscripts to represent the number and types of elements contained in a molecule. A chemical formula seems to be a concise written description of an existing three-dimensional molecule.
A chemical formula characterizes a material to the atomic level. There are three sorts of chemical formulas: empirical, molecular, and structural.
The chemical formula for the given molecules are:
2. H[tex]_2[/tex]O
3. O[tex]_3[/tex]
4. H[tex]_2[/tex]
5. CO[tex]_2[/tex]
6. CO
7. NO[tex]_2[/tex]
8. CH[tex]_4[/tex]
Therefore, in the above given ways the chemical formula for the molecule can be written.
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In which substance are molecules moving the fastest? The options are, a. Solid water (ice) b. Liquid water c. Water vapor (gas)
Answer:
The answer is C
Explanation:
The more space the molecules have the faster they will move, solid doesn't allow movement at all, when it gets to liquid they are free to move around because it's more space, when a gas they can move all around in the air.
A student wishes to determine the chloride ion concentration in a water sample at 25 °C using a galvanic cell constructed with a graphite electrode and a half-cell of AgCl(s) + e⁻ → Ag(s) + Cl⁻(aq) E°red = 0.2223 V And a copper electrode with 0.500 M Cu²⁺ as the second half cell Cu²⁺(aq) + 2 e⁻ → Cu(s) E°red= 0.337 V The measured cell potential when the water sample was placed into the silver side of the cell was 0.0925 V. What is the standard cell potential for this cell in V?
The question is incomplete, the complete question is;
And a copper electrode with 0.500 M Cu²⁺ as the second half cell
Cu²⁺(aq) + 2 e⁻ → Cu(s) E°red= 0.337 V
The measured cell potential when the water sample was placed into the silver side of the cell was 0.0925 V.
A- What is the standard cell potential for this cell in V?
B- What is the value of the standard free energy (in kJ) for this reaction?
C- Write the balanced equation for the overall reaction in acidic solution?
D- And the measured cell potential is 0.0925, what is the concentration of chloride ions in the solution?
Answer:
See Explanation
Explanation:
a) E°cell = E°cathode - E°anode
E°cell = 0.337 V - 0.2223 V
E°cell = 0.1147 V
b) ΔG°cell = −nFE°cell
Where n=2 and F = 96500C
ΔG°cell =-(2 * 96500 * 0.1147 )
ΔG°cell =-22,137.1 J or -22.1371 KJ
c) 2Ag(s) + 2Cl⁻(aq) + Cu²⁺(aq) -----> 2AgCl(s) + Cu(s)
d) From Nernst Equation;
E= E°cell - 0.0592/n log Q
0.0925 = 0.1147 - 0.0592/2 log 1/[0.500] [Cl⁻]^2
0.0925 - 0.1147 = - 0.0592/2 log 1/[0.500] [Cl⁻]^2
-0.0222 = -0.0296 log 1/[0.500] [Cl⁻]^2
-0.0222/-0.0296 = log 1/[0.500] [Cl⁻]^2
0.75 = log 1/[0.500] [Cl⁻]^2
Antilog (0.75) = 1/[0.500] [Cl⁻]^2
5.6234 * 0.500 = [Cl⁻]^2
[Cl⁻] = √2.8117
[Cl⁻] = 1.68 M
A galvanic cell is a voltaic cell that produces electrical energy from the oxidation-reduction process. The standard cell potential of the cell is 0.1147 V.
What is standard cell potential?The standard cell potential is a difference between the electrode potential of the cathode and the anode of the cell.
The balanced overall reaction of the cell is given as,
[tex]\rm 2Ag(s) + 2Cl^{-}(aq) + Cu^{2+}(aq) \rightarrow 2AgCl(s) + Cu(s)[/tex]
The standard cell potential is calculated as:
[tex]\begin{aligned} \rm E^{\circ}cell &= \rm E^{\circ}cathode - E^{\circ} anode\\\\&= 0.337 - 0.2223 \\\\&= 0.1147\;\rm V\end{aligned}[/tex]
Therefore, 0.1147 V is the standard cell potential for the cell.
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__________the lowest point on a wave
Answer:
The lowest point on a wave?
The lowest point on the wave is called as through or wave through.
The highest point on the wave is known as the crest or wave crest
The space between the crests is called the wave length.
The distance between the wave crest and the wave trough is called the wave height.
#CarryOnLearning
Answer:
Trough
Explanation:
The trough is the lowest point on a wave. The highest point on a wave is called a crest.
g Given that ammonia (NH3) acts as a weak base in water with a Kb of 1.8 x 10-5 at 298.0 K, calculate the pH at 298.0 K of a solution prepared by mixing 100.0 mL of a 0.050 M aqueous solution of ammonia with 20.0 mL of a 1.00 M aqueous solution of nitric acid. The final volume of the solution is 120.0 mL.
Answer:
pH = 0.90
Explanation:
The NH3 reacts with nitric acid, HNO3 as follows:
NH3 + HNO3 → NH₄⁺ + NO₃⁻
Where 1 mole of NH3 reacts per mole of HNO3.
The moles added of each reactant are:
Moles NH3:
100mL = 0.100L * (0.050mol / L) = 0.0050 moles NH3
Moles HNO3:
20mL = 0.0200L * (1.00mol / L) = 0.0200 moles HNO3
That means HNO3 is the excess reactant and, after the reaction, its moles are:
0.0200mol - 0.0050mol = 0.0150 moles HNO3
In a final volume of 120mL = 0.120L, the molar concentration of HNO3 is:
0.0150 moles HNO3 / 0.120L = 0.125M HNO3
As nitric acid is a strong acid, [HNO3] = [H+]
[H+] = 0.125M
pH = -log[H+]
pH = 0.90Bromine is a red-brown liquid with a density of 3.10 g/mL. A sample of bromine weighing 88.5 g occupies what volume
Answer:
28.55 mL or 0.02855 L
Explanation:
Applying,
Density(D) = mass(m)/Volume(V)
D = m/V............... Equation 1
Where D = Density of the Bromine, m = mass of the bromine, V = volume of the bromine
make V the subeject of the equation
V = m/D............. Equation 2
From the question,
Given: m = 88.5 g, D = 3.10 g/mL
Substitute these values into equation 2
V = 88.5/3.10
V = 28.55 mL
Hence the volume occuppied by the Bromine gas is 28.55 mL or 0.02855 L
200 grams of iron (III) chloride reacts with ammonium carbonate [(NH4)2CO3] in the following equation.
FeCl3 + (NH4)2CO3 ---------> NH4Cl + Fe2(CO3)3
The number of grams of ammonium chloride (NH4Cl) that will be produced is ___ grams.
a
395
b
181
c
198
d
339
Answer:
[tex]FeCl₃ + (NH₄)₂CO₃ → NH₄Cl + Fe₂(CO₃)₃[/tex]
first balance the chemical equation
first balance the chemical equation[tex]2FeCl₃ + 3(NH₄)₂CO₃ → 6NH₄Cl + Fe₂(CO₃)₃[/tex]
2FeCl₃=2*162=324g
6NH₄Cl=6*53.5=321g
324 g of FeCl₃ gives 321 g of NH₄Cl
200g of FeCl₃ gives 321/324*200=198.14 g of NH₄Cl
in nearest value it is 198g/mole
The number of grams of ammonium chloride (NH4Cl) that will be produced is C.198___ grams.A 750-mL sample of hydrogen exerts a pressure of 822 torr at 325 K. What pressure does it exert if the temperature is raised to 475 K at constant volume
Answer:
1.20 × 10³ torr
Explanation:
Step 1: Given data
Initial pressure (P₁): 822 torrInitial temperature (T₁): 325 KFinal pressure (P₂): ?Final temperature (T₂): 475 KConstant volume: 750 mLStep 2: Calculate the final pressure of the gas
Considering the constant volume, if we assume the gas behaves ideally, we can calculate its final pressure using Gay-Lussac's law.
P₁/T₁ = P₂/T₂
P₂ = P₁ × T₂/T₁
P₂ = 822 torr × 475 K/325 K = 1.20 × 10³ torr
Name one major function of the organ systems listed below.
1. Skeletal System
2. Muscular System
3. Digestive System
4. Respiratory System
5. Circulatory System
6. Nervous System
7. Urinary System
Plss help I’ll give u 35 points
The organ system has been defined as the collective working of the organs for performing a specified task. Each organ system has been assigned a major task to be performed.
The function of the following organ systems have been:
Skeletal system: It has been comprised of bones and muscle. The major function of skeletal system has to maintain the body structure, and allow the interaction of muscular system to nervous system.Muscular system: It has been dealing with the voluntary and involuntary muscles. The major function has been the operation of the skeletal system by following the commands from the nervous system.Digestive system: It has been comprised of esophagus, stomach, intestine. The major function has been the breakdown of food and absorption of nutrients.Respiratory system: The respiratory system has been comprised of lungs and trachea. It has a major function of release of harmful gases, as well as oxidation and reduction of the byproducts of glycolysis.Circulatory system: It has been majorly comprises heart. The major function has been purification of blood and transport to different parts of the body.Nervous system: It has been comprised of brain and neurons, the function has been transmission of signals to the stimuli and responsible for conscious and subconscious behavior.Urinary system: The major part has been kidneys and the nephrons. The function has been the filtration of the waste liquid and urination.For more information about organ system, refer to the link:
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1. What is the oxidation state of iron in FeC2O4
Answer:
+2
Explanation:
I am first with correct answer
Answer:
the oxidation state of iron in FeC2O4 is +2
the solubility of alcohol decrease with increasing numbers of carbon atom explain
Explanation:
bdjdiififjc mfkxkdkd has also had a good time in the
5.
When 0.421 g of BaCl2:2H20 and 0.722g of Na3PO4.12H2O mix with water
forming 500 mL of solution, how many grams of Ba3(PO4)2 precipitate?
Explanation:
2H2O and 0.722g of Na3PO4.12H20 mix with water forming 500 mL of solution, how many grams of Ba3(. ... Forming 500 ML Of Solution, How Many Grams Of Ba3(PO4)2 Precipitate?
When 0.421 g of BaCl₂ · 2 H2O and 0.722g of Na₃PO₄ · 12 H₂O mix with water forming 500 mL of solution then 0.003 mol/L of Ba₃(PO4)₂ precipitate.
What is Stoichiometry ?Stoichiometry is an important concept which helps us use the balanced chemical equation to measures the amount of reactants and products.
What is Molarity ?Molarity of solution is the number of moles of solute per liter of solution. Molarity is also called Molar Concentration.
Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]
How to find the number of moles ?Number of moles = [tex]\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
First we have to write the balanced chemical equation
2Na₃PO₄ · 12 H₂O + 3BaCl₂ · 2 H2O → Ba₃(PO4)₂ + 6 NaCl + 30 H₂O
Here 3 moles of BaCl₂ · 2 H2O produce 1 mole of Ba₃(PO4)₂
So,
Number of moles of BaCl₂ · 2 H2O = [tex]\frac{\text{Mass of}\ BaCl_2 . 2H_2O}{\text{Molar mass of}\ BaCl_2. 2H_2O}[/tex]
= [tex]\frac{0.421}{244.26}[/tex]
= 0.017
Number of moles of 2Na₃PO₄ · 12 H₂O = [tex]\frac{\text{Mass of}\ Na_3PO_4. 12H_2O}{\text{Molar mass of}\ Na_3PO_4 . 12H_2O}[/tex]
= [tex]\frac{0.722}{380.12}[/tex]
= 0.002
Therefore, Na₃PO₄ · 12 H₂O is the limiting reagent.
Now, put the value in above formula to find the molarity
Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]
= [tex]\frac{0.0017}{0.5}[/tex]
= 0.003 mol/L
Thus, from above conclusion we can say that 0.003 mol/L of Ba₃(PO4)₂ precipitate.
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which of the following has the largest atomic radius?
Al
B
Ca
N
Answer:
Im not sure if im right but i think its Ca
Explanation:
A 136 g sample of an unknown substance was heated from 20.0 °C to 40.0 °C. In the process the substance absorbed 2440 J of energy. What is the specific heat of the substance? Identify the substance among those listed in Table 2.
A. the specific heat is 0.897 J/g.C, The Substance is aluminum
B. the specific heat is -0.897 J/g.C, The Substance is aluminum
C. the specific heat is 4.184 J/g.C, The Substance is water
D. there's not enough information to determine which is the substance.
Answer:
Option A. The specific heat is 0.897 J/gºC, The Substance is aluminum.
Explanation:
We'll begin by calculating the change in temperature of the substance. This can be obtained as follow:
Initial temperature (T₁) = 20.0 °C
Final temperature (T₂) = 40.0 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 40 – 20
ΔT = 20 °C
Finally, we shall determine the specific heat capacity of the substance. This can be obtained as follow:
Mass (M) = 136 g
Change in temperature (ΔT) = 20 °C
Heat (Q) absorbed = 2440 J
Specific heat capacity (C) =?
Q = MCΔT
2440 = 136 × C × 20
2440 = 2720 × C
Divide both side by 2720
C = 2440 / 2720
C = 0.897 J/gºC
Comparing the specific heat capacity (i.e 0.897 J/gºC) of the substance with those in the table above, the substance is Aluminum.
Thus, option A gives the correct answer to the question.
Is the following chemical equation balanced? Please make a claim, provide evidence, and then explain your reasoning.
2Li + 2H2O H2 + 2LiOH
Answer:
first the right answer is
Li + H2O = LiOH + H2O
then to balance it...
2 Li + 2 H2O = 2 LiOH + H2
so that we can have both side of the equation to be equal....
HOPE ITS HELPS....
Sodium hydroxide, NaOH, is a strong base that is sometimes used as a cleaning agent since it can be used to dissolve proteins, grease, oils, and fats. Rank the following in increasing order of their molarity. Rank from lowest to highest.
a. 6.625 g NaOH dissolved in 250. mL of water
b. 63.0 g of NaOH dissolved in 1.00 L of water
c. 8.00 g of NaOH dissolved in 500. mL of water
d. 0.0530 of NaOH in 100 mL of water
Answer:
Rank from lowest to highest - c<a<d<b
Explanation:
Molarity is basically the moles of the solute dissolved in a solvent. Molar mass of NaOH = 39.997 g/mol
a) 6.625 g NaOH dissolved in 250. mL of water
Molarity = 6.625 grams */( 0.250 *39.997) g/mol = 0.66
b) 63.0 g of NaOH dissolved in 1.00 L of water
Molarity = 63 grams */( 1 *39.997) g/mol = 1.575
c) 8.00 g of NaOH dissolved in 500. mL of water
Molarity = 8 grams */( 0.5 *39.997) g/mol = 0.331
d) 0.0530 of NaOH in 100 mL of water = 0.53
Rank from lowest to highest - c<a<d<b
What is the formula for calculating the pH of a solution
CH4 + 2 CO2 —> 2 H2O What type of chemical reaction is taking place
in this chemical equation?
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
7. water, when heated, changes into this
Answer:
We learned that waterhas three states: ice is the solid state, watervapor is the gaseous state, and wateris the liquid state. When water is heatedit evaporates, which means it turns into watervapor and expands. Secondly, does water expand when heated?
Explanation:
To which family of organic compounds does CH3COCH2CH2CH3 belong?
Answer:
I think:
CH3COCH2CH2CH3 belongs to ketone because it has a carbonyl group C=O in its structure.
A student went to the cafeteria and bought iced tea. He then proceeded to add more sugar to his iced tea. In this solution, the iced tea was the __________ and the sugar was the ____________.
A student enters the canteen and buys iced tea. He then goes on to add more sugar to his iced tea. In this solution, iced tea is the solvent and sugar is the solute.
Give two examples of each of the following:
1.) Physical systems designed by people.
2.) Naturally occurring physical systems.
3.) Social systems that you are a part of.
4.) Naturally occurring social system.
one mole of water weights?
Answer:
c 18.0ml
Explanation:
The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.
Silver nitrate, AgNO3, reacts with ferric chloride, FeCl3, to give silver chloride, AgCl, and ferric nitrate, Fe(NO3)3. In a particular experiment, it was planned to mix a solution containing 25.0 g of AgNO3 with another solution containing 45.0 grams of FeCl3. Write the chemical equation for the reaction.
Answer:
[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]
Explanation:
From the given question,
The chemical equation is:
[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]
We are given that:
mass of [tex]FeCl_3[/tex] = 45 g
number of moles of [tex]FeCl_3[/tex] = 45 g/162.2 g/mol
= 0.28 mol
mass of [tex]AgNO_3[/tex] = 25g
number of moles of [tex]AgNO_3[/tex] = 25/169.87
= 0.147 mol
From the given equation 1 mole of [tex]FeCl_3[/tex] is required to make 3 mole of [tex]AgNO_3[/tex]
0.28 mole of [tex]FeCl_3[/tex] = 0.28 × 3 = 0.84 mol of [tex]AgNO_3[/tex]
Here [tex]AgNO_3[/tex] is the limiting reagent.
Thus,
3 mole of [tex]AgNO_3[/tex] = 3 moles of AgCl
0.147 mole of [tex]AgNO_3[/tex] = 0.147 mole of AgCl produced.