Answer these two questions, please.
1.Why the melting point and boiling point of [tex]H_{2} O[/tex] are lower than metals?
2.Why the melting point and boiling point of [tex]H_{2} O[/tex] are comparatively higher than other non-metals?
Answer:
neom, sodium bicarbonate
Total number of elements present in the 3rd period is;
expand write down the binomial expansion of (1+2x)^7in ascending power of x ,simplifying all the coefficient. use the expansion theory to calculate the value of (0.98)^7 correct to four decimal places.
Answer:
0.86812566700000000000000
The binomial expansion of (1+2x)^7in ascending power of x is 0.868125.
What are binomial expansions?The algebraic expression (x + y)n can be expanded according to the binomial theorem, which represents it as a sum of terms using separate exponents of the variables x and y.
Each word in a binomial expansion has a coefficient, which is a numerical value. A binomial is a two-term algebraic expression. Examples of binomials include a + b, x - y, and more.
When a binomial is raised to exponents 2 and 3, we can use a set of algebraic identities to determine the expansion. As an illustration, (a + b)2 = a2 + 2ab + b2.
By regrouping and combining like phrases, we can arrange our final response in ascending powers of x by placing the lowest power of x first and the highest power of x last.
Therefore, the binomial expansion of (1+2x)^7in ascending power of x is 0.868125.
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Select the correct answer.
What does the empirical formula of a compound describe?
Ο Α. .
the type and number of atoms
OB.
the type and ratio of atoms
O C.
the number of atoms
OD
the type and mass of atoms
Reset
Next
Answer:
b
Explanation:
cause empirical formular is the elementary or the foundation for molecular formula and molecular formula depends on the empirical formula
How many grams of FeCl3 are needed to make 1.5 L of a solution with a molarity of 0.450 M?
What is a surface that reflects a color of 500 nanometer wavelength?
Answer:
something cyan colored?
A gas at constant volume has a pressure of 2.80 atm at 400. K. What will be the pressure of the gas at 360. K? (4 points)
2.52 atm
2.94 atm
3.11 atm
3.78 atm
Option first 2.52 atm
Answer:
Solution given:
pressure 1[P1]=2.8atm
pressure 2[P2]=?
temperature [T1]=400k
temperature [T2]=360k
now
By using gas equation
P1V1/T1=P2V2/T2
since
volume is constant
P1/T1=P2/T2
2.8/400=P2/360
P2=2.8*360/400
P2= 2.52
Answer:
It's 2.52
Explanation:
This requires Gay-Lussac's Law, in which the relationship is P1 / T1 = P2 / T2. "P" stands for Pressure and "T" is Temperature. The first pressure is 2.80, the first temperature is 400 Kelvin, the second pressure is unknown (that's what your solving for), and your second temperature is 360 Kelvin. Because you don't have the second pressure, your equation will look like 2.80 atm x 360 K / 400. This will tell you that the pressure of the gas at 360 K will be 2.52.
I also took the test and it was correct.
Which of the following is not a part of every scientific investigation?
Group of answer choices
Collection of relevant empirical evidence
Using models to understand objects and processes better
Use of logical reasoning
Devising hypothesis, making predictions
Answer:
the correct answer is Group of answer choices
Using models to understand objects and processes better is not part of every scientific investigation while collection of relevant empirical evidence,use of logical reasoning and devising hypothesis, making predictions is a part.
What is hypothesis?Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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A presión de 3atm, 7L de un gas a temperatura constante experimenta un cambio ocupando un volumen de 0,5L ¿Cuál será la presión que ejerce? ayuda
Answer:
La presión que ejerce es 42 atm.
Explanation:
La ley de Boyle relaciona la presión y el volumen y dice que el volumen ocupado por una determinada masa gaseosa a temperatura constante, es inversamente proporcional a la presión.
La ley de Boyle se expresa matemáticamente como:
P*V=k
Ahora es posible suponer que tienes un cierto volumen de gas V1 que se encuentra a una presión P1 al comienzo del experimento. Si varias el volumen de gas hasta un nuevo valor V2, entonces la presión cambiará a P2, y se cumplirá:
P1*V1= P2*V2
En este caso:
P1= 3 atmV1= 7 LP2= ?V2= 0.5 LReemplazando:
3 atm* 7 L= P2* 0.5 L
Resolviendo:
[tex]P2=\frac{3 atm*7 L}{0.5 L}[/tex]
P2= 42 atm
La presión que ejerce es 42 atm.
Answer:10.5
Explanation:
3atm x 7L / 0,5L = 10.5
Quando bajamos el volmen sube la presion y cuando bajamos la presion sube el volumen
an archaeologist discovers an ancient wooden bowl. which isotope would most likely be used to determine its age?
a. carbon-12
b. carbon-14
c. uranium-238
d. oxygen-16
please and thank you to anyone who may know the answer.
Answer:
B
Explanation:
Which of the following molecules or ions has a bent shape?
A: CIO4
B: PH3
C: OF2
D: PCI5
Write a balanced half-reaction for the oxidation of solid manganese dioxide to permanganate ion in basic aqueous solution. Be sure to add physical state symbols where appropriate.
Answer:
8 OH⁻(aq) + Mn(s) ⇒ MnO₄⁻(aq) + 4 H₂O(l) + 7 e⁻
Explanation:
Let's consider the following oxidation half-reaction that takes place in basic aqueous solution.
Mn(s) ⇒ MnO₄⁻(aq)
First, we will perform the mass balance. We will add 4 H₂O to the products side and 8 OH⁻ to the reactants side.
8 OH⁻(aq) + Mn(s) ⇒ MnO₄⁻(aq) + 4 H₂O(l)
Finally, we will perform the charge balance by adding 7 electrons to the products side.
8 OH⁻(aq) + Mn(s) ⇒ MnO₄⁻(aq) + 4 H₂O(l) + 7 e⁻
Analyze the following chemical combinations
a) MgO
b)CaCl2
c) Na2O
Why nitration of benzene is easier than that of benzene......... And how is phenol converted to TNT
Answer:
The nitration of phenol is easier than that of benzene because benzene has delocalised pie-electrons which makes it more stable than phenol.
Phenol is converted to Trinitrotoluene by adding zinc dust to remove the hydroxyl group, then reacted with Aluminium oxide followed by haloalkane.
At which of the four labeled points on the titration curve below do you expect to find the highest concentration of hydroxide
ions?
A
B
C
D
Answer:
D.
Explanation:
Hydroxide ions are produced when acid reacts with a base under a Ph value of more than 7. Hydroxide ions are negatively charged ions which are released in the aqueous solution during titration process. It a oxygen and hydrogen atom covalent bond.
What is the volume of .750 M hydrochloride acid required to react completely with 25.00 mL of .290 M NaOH solution?
from
HCl + NaOH----> NaCl +H2O
n of acid=1
n of base=1
Molarity of acid=750M
Molarity of base=290M
volume of base=25ml
from
Va=Mb ×vb×na
Ma×nb
Va=290×25×1
750×1
Va=7250
750
Va=9.67ml
The volume of .750 M hydrochloride acid is required to react completely with 25.00 mL of .290 M NaOH solution is 9.67ml
HCl + NaOH----> NaCl +H2O
n of acid=1
n of base=1
Molarity of acid=750M
Molarity of base=290M
volume of base=25ml
Therefore,
Va=Mb ×vb×na
Ma×nb
Va=290×25×1
750×1
Va=7250
750
Hence,
Va=9.67ml
What is Hydrochloric acid?
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctively pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the digestive systems of most animal species, including humans. Hydrochloric acid is an important laboratory reagent and industrial chemical.
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20. Show a correct numerical setup for calculating the molarity of the KOH * (aq) solution. Then state the calculated value of the molarity .
Answer:
[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex] ---- The setup
[tex]M_b = 0.25M[/tex] --- The molarity of KOH
Explanation:
Given
I will answer the question with the attached titration data
Required
The set and the value of the molarity of KOH
First, calculate the volume of acid (HCL) used:
[tex]V_a = Final\ Reading - Initial\ Reading[/tex]
[tex]V_a = 25.00mL - 15.50mL[/tex]
[tex]V_a = 9.50mL[/tex]
Calculate the final volume of base (KOH) used:
[tex]V_b = Final\ Reading - Initial\ Reading[/tex]
[tex]V_b = 8.80mL - 5.00mL[/tex]
[tex]V_b = 3.80mL[/tex]
The numerical setup is calculated using::
[tex]M_a * V_a = M_b * V_b[/tex]
Where
[tex]V_a = 9.50mL[/tex]
[tex]V_b = 3.80mL[/tex]
[tex]M_a = 0.10M[/tex] --- the given molarity of HCL
So, we have:
[tex]M_a * V_a = M_b * V_b[/tex]
[tex]0.10M * 9.50mL = M_b * 3.80mL[/tex]
Make Mb the subject
[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex] ---- The correct numerical setup
The solution is then calculated as:
[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex]
[tex]M_b = \frac{0.10 * 9.50}{3.80}M[/tex]
[tex]M_b = \frac{0.95}{3.80}M[/tex]
[tex]M_b = 0.25M[/tex]
a buffer solution is prepared by adding NH4Cl to a solution of NH3 (ammonia). what happens if NaOH is added?
NH3(aq)+ H2O(l) = NH4+(aq) +OH- (aq)
Answer: The reaction proceeds in the backward direction.
Explanation:
A buffer is a solution that maintains the pH of the solution and resists any significant changes of pH on the addition of acid or alkali.
A buffer solution of [tex]NH_4Cl\text{ and }NH_3[/tex] is prepared. It is a basic buffer as it is formed by the combination of a weak base [tex](NH_3)[/tex] and its conjugate acid [tex](NH_4Cl)[/tex]
When a strong base (NaOH) is added to this buffer solution, the ammonium ions releases hydrogen ion to the solution which then combines with the hydroxide ions to form water and ammonia in a solution. Thus, maintaining the pH of the buffer.
The given chemical equation follows:
[tex]NH_3(aq)+H_2O(l)\rightleftharpoons NH_4^+(aq)+OH^-(aq)[/tex]
Hence, the reaction will proceed in the backward direction.
When NaOH is added to this buffer solution it forms water and ammonia.
A buffer is a solution that maintains the pH of the solution and maintains the pH on the addition of acid or alkali.
A buffer solution of [tex]NH_4Cl[/tex] and [tex]NH_3[/tex] is is a basic buffer as it is formed by the combination of a weak base and its conjugate acid.
When a NaOH which is a strong base is added to this buffer solution, the ammonium ions release hydrogen ion which combines with the hydroxide ions to form water and ammonia helps maintain the pH of the buffer.
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Give me formula for
1)Aluminium chloride
2) Copper sulphate
3) Zinc Nitrate
3) Ammonium Carbonate
Answer:
1. AlCl₃
2. CuSO4
3. Zn(NO₃)₂
4. (NH4)2CO3
How many Group 17 elements are in Period 3 of the Periodic Table? A) 1 B) 2 C) 3 D) 4
23. What type of chemical reaction is: CH, + 0→ CO2 + H20
a. Combustion
b. Neutralization
C. Synthesis
d. Double Replacement
Answer:
combustion
Explanation:
bsnszisb idiej jeiieyv
Give the systematic name for PbO2
The systematic name for PbO₂ is lead dioxide.Therefore, the correct option is A.
What are systematic names?Systematic names are a type of chemical nomenclature that follow a systematic set of rules to name chemical compounds. Lead dioxide (PbO₂) is a chemical compound composed of lead and oxygen. It is an oxide of lead and can also be called lead(IV) oxide.
The systematic name of the compound is derived by using the root word of the metal, “lead,” and adding the suffix “-dioxide” to indicate the two oxygen atoms. Thus, the systematic name for PbO₂ is lead-dioxide.Therefore, the correct option is A.
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The question is incomplete, but most probably the complete question is,
Give the systematic name for PbO₂?
A. Lead dioxide
B. Lead trioxide
C. Lead oxide
D. Lead azide
What type of structure are ionic lattices?
Big structures
Small structures
Tiny structures
Giant structures
Answer:
Giant structures
Explanation:
An ionic compound is a giant structure of ions. The ions have a regular, repeating arrangement called an ionic lattice . The lattice is formed because the ions attract each other and form a regular pattern with oppositely charged ions next to each other.
Please solve this question for me.
Answer:
0.0013 moles
Explanation:
moles = volume/ molar volume of gas
=240/24000cm3 (convert dm3 to cm3)
=0.0013
the correct sequence where reactivity towards oxygen increases.
Answer:
Option D is good to go!
Explanation: as per the reactivity series more reactive substances will react with the counterpart substance.The most reactive substance here is calcium while the least reactive is aluminium, the magnesium comes in between.As per their reactivity, these substances will react with oxygen.
Explanation:
what is the state of matter that takes shape of a container???
Answer:
Liquid and gas is the matter that takes shape of a container
It can also be called fluid since fluid is distributed into liquid and gas
Explanation:
I hope that is enough for your answer, hope this will help
what's the common name for hydrogen oxide
Cholesterol has a formula of C27H46O. What is the mass in grams of one molecule of cholesterol?
The molar mass of cholesterol = 386.654 g/mol = 387 g/mole
3.2 mg cholesterol x 1 g/1000 mg x 1 mole/387 g x 6.02x1023 molecules/mole = 5.0x1018 molecules.
The mass in grams of one molecule of cholesterol, C27H46O is 6.43×10⁻²² g
Avogadro's hypothesis6.02×10²³ molecules = 1 mole of Cholesterol
But,
1 mole of Cholesterol = 387 g
Thus,
6.02×10²³ molecules = 387 g mole of Cholesterol
How to determine the mass of one molecule6.02×10²³ molecules = 387 g mole of Cholesterol
1 molecule = 387 / 6.02×10²³
1 molecule = 6.43×10⁻²² g of Cholesterol
Thus, the mass of 1 molecule of cholesterol is 6.43×10⁻²² g
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La formula quimica de la molecula de agua H20 , si H = 1 gramos y O = 16 gramos . Cual es su composicion porcentual ? 88,88 % de O y 11,11 % de H 88,88 % de H Y 11,11% de O 80 % de O Y 20 % de H 90% de O Y 10 % de H
Answer:
88,88 % de O y 11,11 % de H
Explanation:
La composición porcentual se define como la masa que hay de cada mol de átomo en 100g. Las moles de agua en 100g son:
Masa molar agua:
2H = 2*1g/mol = 2g/mol
1O = 1*16g/mol = 16g/mol
Masa molar = 2 + 16 = 18g/mol
100g H2O * (1mol / 18g) = 5.556 moles H2O.
Moles de hidrógeno:
5.556 moles H2O * (2mol H / 1mol H2O) = 11.11 moles H
Moles Oxígeno = Moles H2O = 5.556 moles
La masa de hidrógeno es:
11.11mol * (1g/mol) 11.11g H
La masa de oxígeno es:
5.556 mol * (16g / 1mol) = 88.89g O
Así, el porcentaje de O es 88.89% y el de H es 11.11%. La opción correcta es:
88,88 % de O y 11,11 % de HThis graph represents a population of molecules in a gas versus the distribution of the average velocity(speed) of its molecules in that population. Assume all molecules to be of the same mass. In reading the graph, it is important to note three things. One, is the most probable speed is at the peak of the curve. Secondly, the most probable speed increases as the temperature increases (so shift to the right), and the distribution broadens as it increases.
On the graph, indicate the average kinetic energy of the population.
Explain your answer.
What part of the graph indicates the temperature of the sample?
Explain your answer.
Sketch a curve that represents the distribution of molecules at a temperature below the one shown. Label it as T2. Describe both T and T2 in terms of their average kinetic energy. Be specific and detailed.
Submit your answer below.
Answer:
Part A
Given that the graph is symmetrical and bell shaped, the average kinetic energy is given by the midline of graph, which corresponds to the common speed of the highest number of the population
Part B
The formula for the average kinetic energy, K.E. = (3/2)·(R/NA)·T
Therefore, the part of the graph that indicates the temperature of the sample is the average kinetic energy. K.E.
Part C
At a lower temperature, the heat is less evenly distributed and we have the distribution T2 higher than T1
Please see the attached graph created with MS Visio
Explanation:
