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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This 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:
How many grams of FeCl3 are needed to make 1.5 L of a solution with a molarity of 0.450 M?
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.
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:
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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Name any three organic fertilizer using by farmers ?
Answer:
Typical organic fertilizers include mineral sources, all animal waste including meat processing, manure, slurry, and guano, plant based fertilizers, such as compost, and biosolids.
Match the following quantities
-
6.02 x 1023 atoms of Al
-
1 molecule of N2O
-
6.02 x 1023 molecules of C2H4
-
1 atom of Au
A.
28.05 g
B.
26.98 g
C.
44.01 u
D.
196.97 u
Answer:
C.44.01 u
Explanation:
basta ayan yong answer ko
Suppose you are titrating an acid solution with a base solution of known concentration. To calculate the concentration of the acid solution, use three steps. 1. Use the -------------- { (a) delivered volume (b) volume reading} of base --------------- { (a) after (b) to reach (c) before} the endpoint and the known concentration of the base solution to find the ------------ { (a) moles (b) mass (c) concentration} of base used. 2. Use the ------------ { (a) molar mass (b) dilution equation (c) molar ratio} to find the moles of acid from the moles of base. 3. Divide the moles of acid by the volume of -------------- { (a) base solution before (b) acid solution before (c) acid solution after} the titration to find the concentration of acid.
Answer:
1. (a) delivered volume, (b) to reach, (a) moles
2. (c) molar ratio
3. (b) acid solution before.
Explanation:
1. You must titrate the acid with a base solution of known concentration, and use the (a) delivered volume. At the endpoint, the moles of acid and base in the titration follows the chemical equation, thus, you need (b) to reach the endpoint. With volume and concentration of the base we can find its (a) moles
2. With the (c) molar ratio, we can relate the moles of base with the moles of acid
3. When we have the moles of acid, we just need the volume of (b) acid solution before the titration to find molarity of the acid.
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
what's the common name for hydrogen oxide
How many joules would be required to change the temperature of 250.0 g of aluminum from 15.0°C to 75.0°C? The specific heat capacity of a luminum is 24.2J/g°C.
Analyze the following chemical combinations
a) MgO
b)CaCl2
c) Na2O
which method would be best for separating the compounds of a mixture that is made from two diffrent liquids
Answer:
fractional distillation since ot depends on the different liquids to have different boiling points
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
A gas occupies 25.3 at pressure of 790.5 mmHg. Determine the volume if the pressure is reduced to 8.04 mmHg
Answer:
2487.51.
Explanation:
As per Boyle's law temperature remaining constant the volume of an ideal gas is inversely proportional to its pressure.
pV= k
therefore, p1V1 = p2V2
here V1 = 25.3, p2 = 8.04mm Hg
pressure p1 = 790.5 mm Hg
this means that
25.3×790.5 = 8.04V2
⇒V2= 2487.51
Hence, the required volume is, 2487.51.
A dunk of water holds 550,200 grams of water. How many moles of water are in the tank?
Answer:
12
Explanation:
there are 12 because of the desnity
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:
Calculate the total energy, in kilojoules, that is needed to turn a 46 g block
of ice at -25 degrees C into water vapor at 100 degrees C.
Answer: The total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
Explanation:
Given: Mass = 46 g
Initial temperature = [tex]-25^{o}C[/tex]
Final temperature = [tex]100^{o}C[/tex]
Specific heat capacity of ice = 2.05 [tex]J/g^{o}C[/tex]
Formula used to calculate the energy is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\= 46 g \times 2.05 J/g^{o}C \times (100 - (-25))^{o}C\\= 11787.5 J (1 J = 0.001 kJ)\\= 11.787 kJ[/tex]
Thus, we can conclude that the total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
Draw the structural formula (not the skeletal formula) for 2-octene.
Answer:
Explanation:
2-octene is a structural isomer of octene. Octene is an unsaturated hydrocarbon (alkene) with 8 carbon atoms. The structural formula of 2-octene is seen below
H H H H H H
I I I I I I
H- C - C = C - C - C - C - C - C - H
I I I I I I I I
H H H H H H H H
The structural formula of 2-octene is different from that of octene in the sense that, it's double bond is found in between the second and the third carbon (on the second bond position).
How many Group 17 elements are in Period 3 of the Periodic Table? A) 1 B) 2 C) 3 D) 4
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 HA 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.
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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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⁻
Why can’t neon store energy in this way?
Answer:
Neon is a noble gas, it is monoatomic in nature, which implies that it has only one atom present. If we compare neon with water, water has three atoms present, two hydrogen atoms and one oxygen atom. Hence water stores more energy than neon because it is polyatomic and contains chemical bonds.
Which term refers to energy stored within the center of an atom?
A. Thermal energy
B. Nuclear energy
C. Chemical energy
D. Light energy
Answer: i'm pretty sure it's b if i remember correctly.
Explanation:
i learned this a while ago so i'm not completely sure.
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.
How many molecules of oxygen are in the cylinder
Answer:
A gas cylinder contains exactly 15 moles of oxygen gas (02)
