Answer:
E) 0.0207
Explanation:
The molal concentration, m, is defined as the ratio between moles of solute (In this case, KBr) per kg of solvent (water):
Moles KBr -Molar mass: 119g/mol-
2.21g KBr * (1mol / 119g) = 0.01857moles
Mass solvent:
897g * (1kg / 1000g) = 0.897kg
Molal concentration:
0.01857 moles / 0.897kg =
0.0207m
Right solution is:
E) 0.0207.How many moles are in the 100,000g of CuSO4 • 5H2O ?
Answer:
try (107.87 amu)
Explanation:
Which sentence best describes a bond formed between two unlike atoms?
O A. The bond could form only between two atoms of very different
electronegativities.
O B. The electrons involved in the bond are shared equally between the
atoms.
O C. The bond could have been formed only as the result of ions
attracting each other.
D. The type of bond is determined by the difference in
electronegativity of the atoms.
The type of bond is determined by the difference in electronegativity of the atoms. Hence, option D is correct.
What is a bond?A chemical bond is what holds atoms together in molecules.
The ability of an atom to attract a pair of electrons in a chemical bond is called its electronegativity. The difference in electronegativity between two atoms determines how polar a bond will be.
Hence, option D is correct.
Learn more about bond here:
https://brainly.com/question/7591319
#SPJ2
A sample of radioactive material starts with 80 grams. After 3 half-lives have passed, how much radioactive sample remains?
Answer:
After 3 half lives 10 g of radio active material left.
Explanation:
Given data:
Total amount of radio active material = 80 g
Amount left after 3 half lives = ?
Solution:
At time zero = 80 g
At first half life = 80 g/2 = 40 g
At 2nd half life = 40 g/2 = 20 g
At 3rd half life = 20 g/2 = 10 g
Thus, after 3 half lives 10 g of radio active material left.
what is the molarity of a solution made by adding 0.720 mole of NaOH to 2.40 liters of water
Answer:
Molarity = 0.3 M
Explanation:
Given data:
Moles of NaOH = 0.720 mol
Volume of water = 2.40 L
Molarity = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Molarity = 0.720 mol / 2.40 L
Molarity = 0.3 mol/L
Molarity = 0.3 M
The Earth and the spaceship both have mass. The astronaut is attracted to Earth by gravity, but he is not attracted to the spaceship. Explain.
A sample of an unknown compound is vaporized at 150.°C . The gas produced has a volume of 960.mL at a pressure of 1.00atm , and it weighs 0.941g . Assuming the gas behaves as an ideal gas under these conditions, calculate the molar mass of the compound. Round your answer to 3 significant digits.
Answer:
the molar mass of the compound is 34.0 g /mol
Explanation:
The computation of the molar mass of the compound is as follows:
As we know that
PV = nRT
n = mass ÷ MW
PV = mRT ÷ MW
It can be rearrange as
MW = mRT ÷ (PV)
MW = (0.941)(0.082)(150 + 273) ÷ (1 × 0.96)
= 33.99g/mol
= 34.0 g /mol
Hence, the molar mass of the compound is 34.0 g /mol
How many joules are required to melt 250 grams of water
Answer:
i not sure but i searched it up and it said Q=104525J
Explanation:
What do you have to do to break a molecule?
Answer:
Heat the molecule
Explanation:
Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels.
what is made from a chemical reaction?
Answer:
the Product
Explanation:
Pro
∆G0=-RT in k Known as
Answer:
Gibbs free energy equation
Explanation:
Middle school science help please. ill give brainliest
Answer:
It converts The liquid into a gas at the same temperature.
Explanation:
Answer:
it converts the liquid into gas at the same temperature
Explanation:
when heat is added to a liquid at boiling temperature it converts the liquid into gas at that same boiling temperature
please give brainliest
The red outlined elements have what major characteristics in common?
1 point
Metals, Nonmetals, and Metalloids
One major characteristic they have in common is they are metals.
What is the total charge of an iron nucleus
Write the formula for diphosphorous pentoxide
Answer:
P4O10
Explanation:
How does mass affect a star's life cycle?
O A.
The greater a star's mass, the more likely it is to burn forever.
O B.
The greater a star's mass, the more likely it is to form planets.
O c.
The greater a star's mass, the more likely it is to fuse hydrogen.
D.
The greater a star's mass, the more likely it is to become a black hole.
Answer:
A star's life cycle is determined by its mass. The larger its mass, the shorter its life cycle. A star's mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born. ... As the gas spins faster, it heats up and becomes as a protostar.Explanation:
Read this and then choose your options ✍️✍️How many mL of 0.125 M Ba(OH)2 would be required to completely neutralize 75.0 mL of 0.845 M HCl? What is the pH of the solution at the equivalence point?
Answer:
253.5mL of Ba(OH)₂ are required to neutralize the HCl solution
The pH at equivalence point is = 7
Explanation:
The reaction of Ba(OH)₂ with HCl is:
Ba(OH)₂ + 2HCl → BaCl₂ + 2H₂O
First, we need to find moles of HCl. With these moles and the chemical equation we can find the moles of Ba(OH)₂ and the volume required:
Moles HCl:
75.0mL = 0.075L * (0.845mol / 1L) = 0.063375moles HCl
Moles Ba(OH)₂:
0.06338moles HCl * (1mol Ba(OH)₂ / 2mol HCl) = 0.03169 moles Ba(OH)₂
Volume of the 0.125M Ba(OH)₂:
0.03169 moles Ba(OH)₂ * (1L / 0.125mol) = 0.2535L are required =
253.5mL of Ba(OH)₂ are required to neutralize the HCl solution
As the titration was of a strong acid, HCl, with a strong base, Ba(OH)₂, the pH at equivalence point is = 7
Polonium-214 went through a series of radioactive decays to produce a stable isotope of bismuth-210 choose the correct decay series that would produce bismuth-210
A: Polonium-214 undergoes 2 beta decay and 1 gamma emission
B: Polonium-214 undergoes 1 alpha decay and 2 gamma emission
C: Polonium-214 undergoes 2 alpha decay and 1 beta decay
D: Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
The correct decay series :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles ₀γ⁰ positron particles ₁e⁰ neutron ₀n¹Decay's reaction :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+x+y+z
From this decay reaction can be concluded
mass number decreased by 4
atomic number decreased by 1
Then the most suitable are:
Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
So that the mass number and atomic number are the same both before and after decay
If 18.00 mL of 0.1000 M magnesium hydroxide reacts with 10.00 mL of hydrochloric acid, what is the molarity of the acid solution?
Answer:
0.36M HCl
Explanation:
The reaction of Mg(OH)₂ with HCl is:
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
Where 1 mole of magnesium hydroxide reacts with 2 moles of HCl
To solve this question, we need to find the moles of Mg(OH)₂ that reacted and, with chemical equation, solve for the moles of HCl and its molarity (Using the 10.00mL = 0.01000L) as follows:
Moles of Mg(OH)₂:
18mL = 0.018L * (0.100mol / L) = 0.0018 moles Mg(OH)₂
Moles HCl:
0.0018 moles Mg(OH)₂ * (2 moles HCl / mol Mg(OH)₂) = 0.0036 moles HCl
Molarity HCl:
0.0036 moles HCl / 0.0100L =
0.36M HClWhich of the following statements is true?
Question 10 options:
a chromosome is larger than a cell
a DNA strand is made of many chromosomes
a gene contains may chromosomes
a chromosome contains many genes
Answer:
a chromosome contains many genes
Explanation:
A 12.0% sucrose solution by mass has a density of 1.05 gem, what mass of sucrose is present in a 32.0-mL sample of this solution?
A) 0.126g
B) 3.66g
C) 4.03g
D) 3.84g
E) 280 g
Answer:
Option C. 4.03 g
Explanation:
Firstly we analyse data.
12 % by mass, is a sort of concentration. It indicates that in 100 g of SOLUTION, we have 12 g of SOLUTE.
Density is the data that indicates grams of solution in volume of solution.
We need to determine, the volume of solution for the concentration
Density = mass / volume
1.05 g/mL = 100 g / volume
Volume = 100 g / 1.05 g/mL → 95.24 mL
Therefore our 12 g of solute are contained in 95.24 mL
Let's finish this by a rule of three.
95.24 mL contain 12 g of sucrose
Our sample of 32 mL may contain ( 32 . 12) / 95.24 = 4.03 g
Protons and neutrons are similar because they both:
cause objects to become charged
are attracted to electrons
are found in the nucleus of an atom
have positive charges
Answer:
C. are found in the nucleus of an atom
Explanation:
Protons and Neutrons are always located at the center of the atom also called as the nuclei of the atom and constitute nearly all the mass of the atom, while the electrons revolve around them in orbits called shells. Only protons have a positive charge and electrons have negative charges, due to which only protons and electrons attract each other, while neutrons lack charges or have 'Neutral Charges'.
A solution has a pH of 11.75. Calculate the [H:0*] of the solution
The [H₃0⁺] of the solution : 1.778 x 10⁻¹² M
Further explanationpH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH of solution = 11.75
the [H₃0⁺] of the solution :
[tex]\tt pH=-log[H_3O^+]\\\\11.75=-log[H_3O^+]\\\\(H_3O^+]=10^{-11.75}=1.778\times 10^{-12}[/tex]
#1...TRUE/FALSE, the best way to write a conclusion is to use the RERUN method.?
#2...TRUE/FALSE, an example of an inference is “I saw it rain today.”?
#3...TRUE/FALSE, an example of a quantitative observation is “That is a red doll.”?
#4...TRUE/FALSE, a scientific hypothesis is written as “If [independent variable] Then [dependent variable.]”?
please answer all of them
A metal ion uses d2sp3 orbitals when forming a complex. What is its coordination number and the shape of the complex?
Answer:
Octahedral
Explanation:
The idea of hybridization is a valence bond concept introduced by Linus Pauling and soon became an important explanation for the structure of molecules even in coordination chemistry.
Hybridization involves the mixing of orbitals of appropriate energy to form a new set of orbitals that are more suitable for bonding with ligands.
When one s, two d and three p orbitals are hybridized in complex formation, octahedral complexes are formed.
A candle made of certain wax blend burns at a rate of 44.2 mg/min. What is the value of this burn rate if expressed in grams/hour
Answer:
2.652 g/h.
Explanation:
Burn rate (in mg/min) = 44.2 mg/min
Burn rate (in m/h) =?
We'll begin by converting 44.2 mg/min to g/min. This can be obtained as follow:
1 mg/min = 0.001 g/min
Therefore,
44.2 mg/min = 44.2 mg/min × 0.001 g/min / 1 mg/min
44.2 mg/min = 0.0442 g/min
Finally, we shall convert 0.0442 g/min to g/h. This can be obtained as follow:
1 g/min = 60 g/h
Therefore,
0.0442 g/min = 0.0442 g/min × 60 g/h / 1 g/min
0.0442 g/min = 2.652 g/h
Therefore, 44.2 mg/min is equivalent to 2.652 g/h.
Thus, the burn rate (in m/h) is 2.652 g/h.
The concentration of carbon dioxide in the atmosphere has been increasing for many years. How might this increase affect photosynthesis? (15 points if answered)
Answer:
Carbon dioxide concentrations are rising mostly because of the fossil fuels that people are burning for energy.
THE OH BOND IN WATER IS POLAR BECAUSE
Answer: In the case of water, we know that the O-H covalent bond is polar, due to the different electronegativities of hydrogen and oxygen. Since there are two O-H bonds in water, their bond dipoles will interact and may result in a molecular dipole which can be measured.
Explanation:
A gas sample occupies 4.39 L at 44 ºC. What will be the new volume, using Charles’ Law, if the temperature decreases to 25 ºC?
Hi there! :)
[tex]\large\boxed{x = 2.49 L}[/tex]
Use the proportion for Charles' Law where:
[tex]\frac{v_{1}}{t_{1}}= \frac{v_{2}}{t_{2}}[/tex]
v1 = initial volume
t1 = initial temperature
v2 = final volume
v2 = final temperature
Substitute in the given values into the proportion:
v1 = 4.39 L
t1 = 44° C
t2 = 25°C
v2 = x L
Set up the proportion:
[tex]\frac{4.39}{44} = \frac{x}{25}[/tex]
Cross multiply:
[tex]25 * 4.39 = 44x\\\\109.75 = 44x\\\\x = 2.49 L[/tex]
Answer:
The new volume will be approximately 2.49 L.
Explanation:
We are given that a gas sample occupies 4.39 L at 44° C.
We are also given that we are going decrease the temperature to 25° C.
Charles' Law has a formula which shows the relationship between the volumes of a samples and the temperatures of the samples.
The proportion is shown as:
[tex]\displaystyle \bullet \ \ \ \frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex],
where V₁ and V₂ are the initial and final volume respectively and T₁ and T₂ are the initial and final temperature respectively.
This proportion can be used to determine what our unknown is. We need to know the final volume.
[tex]\displaystyle \frac{4.39 \ \text{L}}{44 \ \text{C}} = \frac{\text{x}}{25 \ \text{C}}\\\\\\\frac{4.39}{44} = \frac{x}{25}\\\\\\4.39 \times 25 = 44 \times x\\\\\\44x = 109.75\\\\\\\frac{44x}{44}=\frac{109.75}{44}\\\\\\x = 2.49432 \approx \boxed{2.49 \ \text{L}}[/tex]
Therefore, if we reduce the temperature to 25 °C, we will be reducing the volume of the substance to 2.49 L.
These allow electricity to flow easily through them (think copper and aluminum).
(Lessons 5.01-5.03)
Insulators
Electric Currents
Conductors
Resistors
Answer:
conductors
Explanation:
An element has three isotopes. The masses and % abundances for the isotopes are: Isotope #1 mass 38.96 amu, % abundance=93.26%, Isotope #2 mass
39.96 amu, % abundance 0.012 %, and Isotope #3 mass= 40.96 amu, % abundance=6.73 %. The average atomic mass for this element has to be
Answer:
39.095
Explanation:
this is because all this isotopes belong to a single element thus
(38.96×93.26)+(39.96×0.012)+(40.96×6.73)
answer of that divided by 100%
