Answer:
If some of the stearic-acid hexane solution had evaporated before using it, this would increase Avogadro's number, or the number of atoms per mole. This is because with less hexane in the solution (because only the hexane evaporates), the grams of stearic acid used would be smaller.
Explanation:
If some of the stearic-acid hexane solution evaporated before using it, this would increase Avogadro's number or the number of atoms per mole. This is because grams of stearic acid used would be smaller, with less hexane in the solution .
What is Avogadro's number?Proportionality factor that relates number of constituent particles in a sample with the amount of substance in that sample is called Avogadro constant .
Avogadro's number is equal to 6.02214076 × 1023. The units can be electrons, atoms, ions, or molecules, depending on the nature of the substance and the character of the reaction .
Avogadro's law is used to for the relationship between the amount of gas and the volume . Volume of a gas is proportional to the number of moles in the gas sample as it's a direct relationship.
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Which are correct ???
Answer:
last one
Explanation:
endothermic reactions release energy
What mass in grams of MgSO4 is required to make 59.3 mL of 2.68 M
solution?
Answer:
Approximately [tex]19.1\; \rm g[/tex].
Explanation:
Number of moles of formula units of magnesium sulfate required to make the solutionThe unit of concentration in this question is "[tex]\rm M[/tex]". That's equivalent to "[tex]\rm mol \cdot L^{-1}[/tex]" (moles per liter.) In other words:
[tex]c(\mathrm{MgSO_4}) = 2.68\; \rm M = 2.68\; \rm mol \cdot L^{-1}[/tex].
However, the unit of the volume of this solution is in milliliters. Convert that unit to liters:
[tex]\displaystyle V = 59.3\; \rm mL = 59.3 \; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.0593\; \rm L[/tex].
Calculate the number of moles of [tex]\rm MgSO_4[/tex] formula units required to make this solution:
[tex]\begin{aligned}n(\rm MgSO_4) &= c \cdot V \\ &= 2.68 \; \rm mol \cdot L^{-1} \times 0.0593\; \rm L \approx 0.159\; \rm mol \end{aligned}[/tex].
Mass of magnesium sulfate in the solutionLook up the relative atomic mass data of [tex]\rm Mg[/tex], [tex]\rm S[/tex], and [tex]\rm O[/tex] on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm S[/tex]: [tex]\rm 32.06[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Calculate the formula mass of [tex]\rm MgSO_4[/tex] using these values:
[tex]M(\mathrm{MgSO_4}) = 24.305 + 32.06 + 4 \times 15.999 \approx 120.361\; \rm g \cdot mol^{-1}[/tex].
Using this formula mass, calculate the mass of that (approximately) [tex]0.159\; \rm mol[/tex] of [tex]\rm MgSO_4[/tex] formula units:
[tex]\begin{aligned}m(\mathrm{MgSO_4}) &= n \cdot M \\&\approx 0.159 \; \rm mol \times 120.361 \; \rm g \cdot mol^{-1} \approx 19.1\; \rm g\end{aligned}[/tex].
Therefore, the mass of [tex]\rm MgSO_4[/tex] required to make this solution would be approximately [tex]19.1\; \rm g[/tex].
How and why was the periodic table set up?
please help 10 points asap
Answer:
opposite
Explanation:
Answer:
opposite
Explanation:
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A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.
Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.
What is the final temperature of the two pieces of metal expressed in degree C?
Answer:
349.22°C
Explanation:
Let the final temperature of the two pieces of metal be x.
Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.
The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.
Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.
Thus;
q_lost = q_gain
Where;
q_lost = m1•c1•Δt1
q_gained = m2•c2•Δt2
Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.
From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C
We are given;
m1 = 12g and m2 = 15g
Thus;
12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)
2194.5 - 4.62x = 6.9x - 1828.5
6.9x + 4.62x = 2194.5 + 1828.5
11.52x = 4023
x = 4023/11.52
x = 349.22°C
Which is located inside the lung?
Answer:what are the options????
Explanation:
Answer:
D. The Alveoli.
Explanation:
Given the two half-reactions, what must be done in the next step before the reaction can be balanced?
First: upper A u superscript 3 plus right arrow upper A u. Second: upper I superscript minus right arrow Upper I subscript 2.
How many electrons are produced/used in this redox reaction when it is balanced?
2
3
6
Answer:
Given the two half-reactions, what must be done in the next step before the reaction can be balanced?
Answer: Show the number of electrons being lost or grained.
Explanation:
For a two given half-reactions, before the reaction can be balanced determine the number of electrons being lost or grained.
What is a half-reaction?A half reaction is either the oxidation or reduction reaction component of a redox reaction.
The half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction.
Thus, for a two given half-reactions, before the reaction can be balanced determine the number of electrons being lost or grained.
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7. The charge on the electron cloud
A. prevents compounds from forming.
В. balances the charge on the nucleus.
C attracts electron clouds in other atoms to form
compounds.
D does not exist.
Will give brainliest, Look at the graph above. Compare it to the periodic table. What do you notice about the location on the periodic table of the elements that represent the high points
Answer:
We can see that the atomic radius decreases across every row.
Explanation:
I will comment more below.
The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.
The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.
Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.
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Glucose is broken down into
contraction
which is a usable form of energy used to perform processes in living cells such as muscle
O DNA
О АТР
O Enzymes
O Sucrose
what molecule that cells mainly use to grow and build muscle is?
Answer:
Muscle cells use fatty acids, glucose, and amino acids as energy sources. Most cells use glucose for ATP synthesis, but there are other fuel molecules equally important for maintaining the body's equilibrium or homeostasis
Explanation:
Answer:
Most cells use glucose for ATP synthesis, but there are other fuel molecules equally important for maintaining the body's equilibrium or homeostasis. Indeed, although the oxidation pathways of fatty acids, amino acids, and glucose begin differently, these mechanisms ultimately converge onto a common pathway, the TCA cycle, occurring within the mitochondria (Figure 1). As mentioned earlier, the ATP yield obtained from lipid oxidation is over twice the amount obtained from carbohydrates and amino acids.
HELP
What type of bond is formed between the carbon and either oxygen in CO2?
A) Single
B) Double
C) Triple
what are the value and units for the speed of light
Answer:
299,792,458
Explanation:
6) Given that the density of olive oil is 0.92 g/mL, calculate the followin a. The mass of 20.0 mL of olive oil. The volume of 20.0 g of olive oil.
We are given:
Density of Olive oil = 0.92 g / mL
Mass of 20 mL Olive oil:
We know that the density = 0.92 grams / mL
multiplying the numerator and the denominator by 20
Density = 0.92 * 20 grams / 20 mL
Density = 18.4 grams / 20 mL
So, we have 18.5 grams in 20 mL of Olive oil
Volume of 20 grams Olive oil:
We need to multiply the numerator and the denominator of density by a number, that when multiplied by 0.92 will give 20
let that number be x:
0.92 * x = 20
x = 20/0.92
x = 21.74 (approx)
Multiplying the numerator and the denominator by x:
Density = 0.92 grams / 1 mL
Density = 0.092 * 21.74 / 21.74 mL
Density = 20 grams / 21.74 mL
So, we can see that 20 grams of the oil will have the volume 21.74 mL
CALCULATION OF DENSITY:
The density of a substance can be calculated by dividing the mass by its volume. That is;Density = mass (g) ÷ volume (mL)
The density of olive oil is given as: 0.92g/mL
QUESTION 1:
Hence, the mass of 20mL (volume) olive oil is calculated as follows:Mass = density × volume
Mass = 0.92g/mL × 20
Mass of olive oil = 18.4grams.
QUESTION 2:
The volume of 20g (mass) of olive oil is calculated as follows:Volume = mass ÷ density
Volume = 20 ÷ 0.92
Volume of olive oil = 21.74mL
Therefore;
The mass of 20mL of olive oil is 18.4gThe volume of 20g of olive oil is 21.74mLLearn more: https://brainly.com/question/2040396?referrer=searchResults
An atom has 8 protons, 8 neutrons and 9 electrons. is thus a cation, anion, or neutral atom?
Answer:
It is an Anion because there are more electrons than protons making it negative
If the stack of bricks on the right has a mass of 240 kg, approximately what is the mass of the stack of bricks on the left?
A.
2400 kg
B.
720 kg
C.
320 kg
D.
480 kg
Answer:
720
Explanation: study island
Answer:
720
Explanation:
How many orbitals in an atom can have each of the following designations?
(a) 4s
(b) 5f
(c) 6p
(d) n=1
Which of the following elements has 3 electrons in the 2p sublevel?
O A. O
O B. C
O C. B
O DN
Answer:
the answer is D. N
AP3X
According to electronic configuration, there are 3 electrons in the 2p sublevel ,hence the correct option is D.
Electronic configuration is defined as the distribution of electrons that are present in an atom or molecule in an atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is important for understanding the structure of periodic table. It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions so as to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in their ground state and hence are said to be stable.
Thus, the correct option is D.
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______ bonds form when 2 metal atoms share electrons.
A rock rolls down a hill. Which form of energy is this an example of?
Chemical
Electrical
Mechanical
Thermal
Answer:
Mechanical
Explanation:
chemical
Explanation:
I took test 2020
17. Which is a fat-soluble vitamin?
O vitamin B
O vitamin C
O vitamin A
What most likely to cuase the rate of a chemical reaction to increase
Answer:
An increase on temperature.
Explanation:
Answer: adding a catalyst or increasing temperature
Explanation:
A chemical formula includes the symbols of the elements in the
compound and the subscripts that indicate*
how many atoms or ions of each type are combined in the simplest unit
the formula mass
the number of moles in each element
the charges of the elements or ions
Answer:
it indicates, how many atoms or ions of each type are combined in the simplest unit.
Which of the following mixtures may be act as a buffer solution?View Available Hint(s)Which of the following mixtures may be act as a buffer solution?HF, NaFHBr, NaBrHCl, NaClHI, NaI
Answer:
HF, NaF
Explanation:
A buffer system may be formed in one of the following ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Which of the following mixtures may act as a buffer solution?
HF, NaF. YES. HF is a weak acid and F⁻ (from NaF) is its conjugate base.HBr, NaBr. NO. HBr is a strong acid.HCl, NaCl. NO. HCl is a strong acid.HI, NaI. NO. HI is a strong acid.Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE
Answer:
The answer is true
Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.
polyatomic ions with identical molecular formula called?
calculate the number of atoms of each type in 5.3 gram of sodium carbonate
Number of atoms = number of moles x 6.02 x 10²³
Further explanationThe mole is the number of particles contained in a substance
1 mol = 6.02 x 10²³ particles
mol of Sodium carbonate-Na₂CO₃
MW = 106 g/mol
Namass Na
[tex]\tt \dfrac{2\times 23}{106}\times 5.3=2.3[/tex]
mol Na
[tex]\tt \dfrac{2.3}{23}=0.1[/tex]
number of atoms = 0.1 x 6.02 x 10²³ = 6.02 x 10²²
Cmass C
[tex]\tt \dfrac{12}{106}\times 5.3=0.6[/tex]
mol C
[tex]\tt \dfrac{0.6}{12}=0.05[/tex]
number of atoms = 0.05 x 6.02 x 10²³ = 3.01 x 10²²
Omass O
[tex]\tt \dfrac{3.16}{106}\times 5.3=2.4[/tex]
mol O
[tex]\tt \dfrac{2.4}{16}=0.15[/tex]
number of atoms = 0.15 x 6.02 x 10²³ = 9.03 x 10²²
TRUE OR FALSE QUESTIONS
1) ___________________________ The physical properties of metals include
dullness, malleability, ductility, and conductivity.
2) ___________________________ Neutrons have a negative charge.
3) ___________________________Mendeleev was known as the father of the
periodic table.
1: FALSE The physical properties of metals include shininess, malleability, ductility, and conductivity.
2: FALSE Neutrons are the particles in an atom that have a neutral charge. They aren't positive like protons. They aren't negative like electrons.
3: TRUE Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. He is best remembered for formulating the Periodic Law and creating a farsighted version of the periodic table of elements. He is also known as the "father of the periodic table"
Answer:
1.T, 2.F., 3.T
Explanation:
2 is false because electrons have a negative charge neutrons have no charge
How many joules are released when 30.0 g of H2O(g) condenses at 100°C?
Answer:
-6.78 × 10⁴ J
Explanation:
When water condenses (goes from the gaseous state to the liquid state) it releases energy in the form of heat. We can calculate this heat using the following expression.
Q = ΔH°cond × m
where,
Q is the heat released
ΔH°cond is the latent heat of condensation (ΔH°cond of water is -2260 J/g)
m is the mass
Q = ΔH°cond × m
Q = -2260 J/g × 30.0 g
Q = -6.78 × 10⁴ J
The net force on a vehicle that is accelerating at a rate of 1.5m/s^2 is 1,800 newtons. What is the mass of the vehicle to the nearest kilogram?
Answer:
Explanation:
Net force F = 1800 N
acceleration a = 1.5 m /s²
mass = m
mass = force / acceleration
= 1800 / 1.5
m = 1200 kg
The mass of the vehicle to the nearest kilogram is 1200 Kg
The force acting on an object is defined by the following equation
Force (F) = mass (m) × Acceleration (a)
F = ma
With the above formula, we can obtain the mass of the vehicle as follow:
Force (F) = 1800 N
Acceleration (a) = 1.5 m/s²
Mass (m) =?[tex]m = \frac{F}{a} \\ \\ m = \frac{1800}{1.5} \\ \\ m = 1200 \: Kg[/tex]
Therefore, the mass of the vehicle is 1200 Kg
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