Manuel wants to determine how fast a toy car will move across different surfaces. He lines 3 ramps with different surface covers including wax paper, sandpaper, and smooth carpet and runs the same car down each ramp to determine how long it takes for the car to reach the bottom. What is Manuel's independent variable in this experiment
Which of the following substances will cause the least temperature change if the same amount of each substance is added to 1.0 kg of water?
K3PO4
CuSO4
CH4OH
MgCl2
This is a question based on colligative property
colligative property is a property of solution which depends upon the number of molecules of solute and solvent
It is independent of nature of solute added to a particular solvent
The colligative properties are
a) elevation in boiling point
b) depression in freezing point
c) relative lowering of vapour pressure
d) osmotic pressure
As given we are adding same mount of each substance
Which means that we are adding same moles of each substance
the minimum number of particles will be produced by CH3OH (methanol) hence it will cause least temperature change.
The greatest change will be due to K3PO4
Consider the heating curve. In which region are most particles moving the fastest?
A) 2
B) 3
C) 4
D) 5
The particles are moving fastest in Region D) 5.
As temperature increases, so does the average kinetic energy (speed) of the molecules.
Answer: The correct option is (D)
Explanation:
As the temperature increases the energy of the particles increases which results in increase of kinetic energy of the particles. With this increase in energy particles moves more rapidly.
So, the particles at higher temperature will be moving at faster speed in region 5.
[07.01]When ammonia, NH3, dissolves in water, hydrogen ions are transferred from the water to ammonia to form ammonium ions and hydroxide ions. This reaction can be seen below: H2O (l) + NH3 (aq) OH- (aq) + NH4+ (aq) Which of the following helps to explain why ammonia is a base?
Ammonia acts as a Brønsted-Lowry base because it accepts a hydrogen ion from water, forming ammonium and hydroxide ions. It also satisfies the Arrhenius definition by increasing the concentration of hydroxide ions in the solution. Thus, the answer most appropriately corresponds to option b, Brønsted-Lowry definition.
When ammonia, [tex]NH_3[/tex], dissolves in water, it functions as a base according to the Brønsted-Lowry definition because it accepts a hydrogen ion (H+) from water to form ammonium ions ([tex]NH_4^+[/tex]) and hydroxide ions ([tex]OH^-[/tex]). Water acts as a Brønsted-Lowry acid in this reaction because it donates a hydrogen ion to the ammonia. This process forms a conjugate acid-base pair, with ammonia being the base that becomes the conjugate acid ([tex]NH_4^+[/tex]), and water being the acid that becomes the conjugate base ([tex]OH^-[/tex]). Additionally, ammonia also meets the Arrhenius definition of a base because the reaction results in an increase in the concentration of hydroxide ions in the solution. Thus, the answer most appropriately corresponds to option b, Brønsted-Lowry definition.
complete the tables of value for four aqueous solutions at 25 celcius
The table of values for four aqueous solutions at is as shown in Table 1.
Further Explanation:
The negative logarithm of hydrogen ion concentration is termed as pH while that of hydroxide ion concentration is pOH. Higher the pH of solution, more will be the alkalinity and vice-versa. Similarly, higher value of pOH indicates solution is acidic in nature .
The expression for pH is mentioned below.
[tex]\text{pH}=-\text{log}\left[\text{H}^+\right][/tex] ...... (1)
Where [tex]\left[\text{H}^+\right][/tex] is the concentration of hydrogen ion.
The expression for pOH is mentioned below.
[tex]\text{pOH}=-\text{log}\left[\text{OH}^-\right][/tex] ...... (2)
Where [tex]\left[\text{OH}^-\right][/tex] is the concentration of hydroxide ion.
pH and pOH are related to each other by following expression:
pH + pOH = 14 …… (3)
Solution A:
Substitute [tex]6.4\times10^{-13}\text{ M}[/tex] for [tex]\left[\text{H}^+\right][/tex] in equation (1).
[tex]\begin{aligned}\text{pH}=&-\text{log}\left[6.4\times10^{-13}\text{ M}\right]\\=&12.2\end{aligned}[/tex]
Rearrange equation (3) for pOH.
pOH = 14 – pH …… (4)
Substitute 12.2 for pH in equation (4).
[tex]\begin{aligned}\text{pOH}=&14-12.2\\=&1.8\end{aligned}[/tex]
Rearrange equation (2) for [tex]\left[\text{OH}^-\right][/tex] .
[tex]\left[\text{OH}^-\right]=10^{-\text{pOH}}[/tex] …… (5)
Substitute 1.8 for pOH in equation (5).
[tex]\begin{aligned}\left[\text{OH}^-\right]=&10^{-\text{1.8}}\\=&0.016\text{ M}\end{aligned}[/tex]
Solution B:
Substitute [tex]2.7\times10^{-10}\text{ M}[/tex] for [tex]\left[\text{OH}^-\right][/tex] in equation (2).
[tex]\begin{aligned}\text{pOH}=&-\text{log}\left[2.7\times10^{-10}\text{ M}\right]\\=&\ 9.6\end{aligned}[/tex]
Rearrange equation (3) for pH.
pH = 14 – pOH …… (6)
Substitute 9.6 for pOH in equation (6).
[tex]\begin{aligned}\text{pH}=&14-9.6\\=&4.4\end{aligned}[/tex]
Rearrange equation (1) for [tex]\left[\text{H}^+\right][/tex] .
[tex]\left[\text{H}^+\right]=10^\text{-pH}[/tex] …… (7)
Substitute 4.4 for pH in equation (7).
[tex]\begin{aligned}\left[\text{H}^+\right]=&10^\text{-4.4}\\=&0.0000398\text{ M}\end{aligned}[/tex]
Solution C:
Substitute 8.11 for pH in equation (7).
[tex]\begin{aligned}\left[\text{H}^+\right]=&10^\text{-8.11}\\=&0.0000000078\text{ M}\end{aligned}[/tex]
Substitute 8.11 for pH in equation (4).
[tex]\begin{aligned}\text{pOH}=&14-8.11\\=&5.89\end{aligned}[/tex]
Substitute 5.89 for pOH in equation (5).
[tex]\begin{aligned}\left[\text{OH}^-\right]=&10^{-\text{5.89}}\\=&0.000001288\text{ M}\end{aligned}[/tex]
Solution D:
Substitute 4.73 for pOH in equation (5).
[tex]\begin{aligned}\left[\text{OH}^-\right]=&10^{-\text{4.73}}\\=&0.00001862\text{ M}\end{aligned}[/tex]
Substitute 4.73 for pOH in equation (6).
[tex]\begin{aligned}\text{pH}=&14-4.73\\=&9.27\end{aligned}[/tex]
Substitute 9.27 for pH in equation (7).
[tex]\begin{aligned}\left[\text{H}^+\right]=&10^\text{-9.27}\\=&0.0000000005\text{ M}\end{aligned}[/tex]
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Answer details:
Grade: High School
Chapter: Acids, base and salts
Subject: Chemistry
Keywords: pH, pOH, H+, OH-, solution A, solution B, solution C, solution D, hydrogen ion, hydroxide ion, negative logarithm.
in which situation can a mixture always be called a solution
Answer: when the mixture is homogeneous
Explanation:
Give the chemical symbol of an element in the third period (row) of the periodic table with three valence electrons. Express your answer as a chemical symbol
What cellular process converts solar energy into chemical energy
a race car driver drives 35 laps in 84 minutes what is the average laps per minute
neon has an average atomic mass of 20.2 g/mol, whereas argon has an average atomic mass of 40.0 g/mol. How would the number of atoms in a 1.0 mol sample of neon compare to the number of atoms in a 4.0 mol sample of argon
Answer : The number of atoms in a 4.0 mole sample of argon has greater number of atoms or four times as compared to the number of atoms in a 1.0 mole sample of neon.
Explanation :
As we know that the 1 mole of substance contains [tex]6.022\times 10^{23}[/tex] number of atoms.
As per question,
The 1 mole sample of neon contains [tex]6.022\times 10^{23}[/tex] number of atoms.
And,
As, 1 mole sample of argon contains [tex]6.022\times 10^{23}[/tex] number of atoms
So, 4.0 mole sample of argon contains [tex]4.0\times 6.022\times 10^{23}=24.088\times 10^{23}[/tex] number of atoms
From this we conclude that, the number of atoms in a 4.0 mole sample of argon has greater number of atoms or four times as compared to the number of atoms in a 1.0 mole sample of neon.
Which substance will most affect the freezing point of water if 1 mole of the substance is added to 1 kilogram of water?
The concentration of 150.0 mL of Na2CO3 is found to be 30.0 ppm. What mass of Na2CO3 is dissolved in the solution if the density of the solution is 0.750 g/mL?
Answer:
c
Explanation:
3.38x10^-3G
What do all steroids have in common?
A. They are not lipids.
B. They are all built on a four-ring structure.
C. They all have the same function.
D. They are all sex hormones.
. How many moles of ammonia gas, NH3, are required to fill a volume of 50 liters at STP?
Answer:2.23 moles
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass , occupies 22.4 Liters at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given volume}}{\text{Molar volume}}=\frac{50}{22.4}=2.23moles[/tex]
Thus 2.23 moles of ammonia gas are required to fill a volume of 50 liters at STP.
the steps of scientific method in order are?
a. purpose , experiment, hypothesis , analysis , conclusion
b. purpose , hypothesis , experiment , analysis, conclusion
c. hypothesis , experiment , analysis, conclusion .
d. purpose, hypothesis, experiment , conclusion
The upper quartile of a set of data is a number that __________. A. separates the bottom half of the data set from the upper half B. finding the mean of the data set remaining after removing the lower half C. separates the lower quarter of the data set from the upper three-quarters D. separates the lower three-quarters of the data set from the upper quarter
Answer:
D. separates the lower three-quarters of the data set from the upper quarter
Explanation:
The upper quartile is a line or a point that divides the upper half of a set of data in two exact parts, so when you get the median of the whole set of data, you take the upper half and calculate the median of that upper half, dividing the upper half in quartiles, and you get the division between the upper quartile and the other three quartiles.
For the reaction Pb(NO3)2 + 2KI → PbI2 + 2KNO3, how many moles of lead iodide are produced from 246.2 g of potassium iodide?
To find out how many moles of lead iodide are produced from 246.2 g of potassium iodide, first convert the mass of KI to moles using its molar mass, then divide by the stoichiometric ratio from the reaction. It is found that 246.2 g of KI will produce 0.7415 moles of lead iodide.
To determine how many moles of lead iodide are produced from 246.2 g of potassium iodide (KI), it is necessary to consider the stoichiometry of the reaction given by:
[tex]Pb(NO_3)_2 (aq) + 2 KI (aq) \rightarrow PbI_2 (s) + 2 KNO_{3} (aq)[/tex]
First, we calculate the number of moles of KI using its molar mass:
1 mole KI = 166.0028 g/mol. Therefore,
Moles of KI = 246.2 g
166.0028 g/mol = 1.483 moles of KI
Since the reaction requires 2 moles of KI for every mole of [tex]PbI_2[/tex], we divide the moles of KI by 2 to find the moles of [tex]PbI_2[/tex]:
[tex]PbI_2[/tex]moles = 1.483 moles / 2 = 0.7415 moles of [tex]PbI_2[/tex]
Therefore, 246.2 g of KI will produce 0.7415 moles of lead iodide.
The modern periodic table is organized by:___________?
Possible Answers: atomic number,number of protons in each element,atomic weight,chemical properties,
The modern periodic table is largely organized by the atomic number of each element. Although atomic weight and chemical properties also play a role, they come secondary to atomic number.
Explanation:The modern periodic table is primarily organized on the basis of the atomic number of each element. The atomic number is equal to the number of protons in the nucleus of an atom of an element. While other factors such as atomic weight and chemical properties are also significant, they are considered secondary in the structure. For example, Hydrogen has an atomic number of 1, hence it is the first element in the Periodic Table. Similarly, Helium with an atomic number of 2 is the second element and so on.
Learn more about Organization of Periodic Table here:https://brainly.com/question/18771645
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Violent shaking from an earthquake can cause soil and rock on slopes to fall and cause a _____.
If 7.84 × 107 J of energy is released from a fusion reaction, what amount of mass in kilograms would be lost? Recall that c = 3 × 108 m/s.
7.06 × 1024
8.71 × 10-4
8.71 × 10-7
8.71 × 10–10
Answer:
The amount of mass in kilograms would be lost [tex]8.7111\times 10^{-10} kg[/tex].
Explanation:
Energy released during fusion reaction = [tex]7.84\times 10^7 J[/tex]
Mass of amount lost during the reaction = Δm
Speed of the light = c = [tex]3\times 10^8 m/s[/tex]
Using Einstein equation :
[tex]E=\Delta m\times c^2[/tex]
[tex]7.84\times 10^7 J=\Delta m\times (3\times 10^8 m/s)^2[/tex]
[tex]\Delta m=8.7111\times 10^{-10} kg[/tex]
The amount of mass in kilograms would be lost [tex]8.7111\times 10^{-10} kg[/tex].
How is scientific use of the term digital different from the common use?
We commonly know refer to something 'digital' has to something electronic that can be visibly seen such as a watch, clock, camera, screen, etc. It really refers to stored energy or electricity that's not natural. But the word 'digital' in science refers to the depiction of data or information in figures (such as in a table) in contrast to as a chart, graph, drawing, or other pictorial form.
Explanation:
The scientific use of the term digital is much changed from the current use because the term digital in science is a way of representing a discontinuous phenomenon or something this is just finite and faulty. It also describes a data in figures with the use of this term. While “digital” generally refers to electronics in general, the scientific explanation of digital is much different
A buret containing NaOH solution has an initial volume reading of 0.14 mL.
25.00 mL of 0.1000 M HCl is titrated to a phenolphthalein end point, which occurs at a final reading of 27.16 mL NaOH. What is the molarity of the NaOH titrant?
Answer:
0.092 M
Explanation:
NaOH(aq) + HCl(aq) ------> NaCl(aq) + H2O(l)
CA= concentration of acid= 0.1000 M
CB= concentration of base= ?????
VA= volume of acid= 25.00 mL
VB= volume of base= 27.16 mL
NA= number of moles of acid= 1
NB= number of moles of base= 1
CAVA/CBVB= nA/nB
CB= CAVAnB/VBnA
CB= 0.1000 M × 25.00 mL ×1/27.16 mL ×1
CB= 0.092 M
A student does not observe a change when holding a test tube in a flame. However, a change is expected. What is the most likely reason for this?
D. The reactants were not heated long enough.
why is it important to have a controlled experiment
What is the mass of exactly 1 mol of the following elements osmium, Cesium, krypton?
]Aluminum ions form an ionic bond with chromate ions, and the resultant formula is Al2(CrO4)3. What is the ion charge for the chromate ion?
In the compound Al2(CrO4)3, the aluminum ion (Al) has a 3+ charge. To balance the electrical neutrality, each chromate ion (CrO4) must have a 2- charge since three of them are needed to balance the 6+ charge from two aluminum ions.
Explanation:Chromate ion has a charge of 2-. When forming an ionic bond with aluminum ions which have a 3+ charge, the formula becomes Al2(CrO4)3.
To determine the ion charge for the chromate ion in the compound Al2(CrO4)3, we must first understand the charges of the ions involved. Aluminum (Al) forms a cation with a 3+ charge, as indicated by the formula. Since the formula of the compound is electrically neutral and contains two aluminum ions, the total positive charge contributed by aluminum is 6+ (2 ions * 3+).
The compound then must have an equivalent total negative charge to balance this, contributed by three chromate (CrO4) ions. For the charges to balance out, each chromate ion must carry a 2- charge (6+ from Al3+ is balanced by 6- from three 2- ions), making the formula for the ionic compound Al2(CrO4)3 electrically neutral. Therefore, the chromate ion has a 2- charge in this compound.
Which of the following represents a purely covalent bond?
Ne – Ne
Na – Na
N – N
Ni – O
when the volume of a gas is changed from _____ m3 to 15.5 m3 the temperature will change from 159 K to 456 K
CH2 - CH2 - CH3
|
CH3 - CH2 - CH - CH2 - CH = CH2
how many grams of sugar are in six dozen doughnuts if each doughnut contains 75 g of sugar?