Answer:
Mass = 15.12 g
Explanation:
Given data:
Mass of sodium borohydride = ?
Number of moles of sodium borohydride =0.40 mol
Solution:
Formula:
Mass = number of moles / molar mass
Molar mass of sodium borohydride = 37.8 g/mol
By putting values,
Mass = 0.40 mol × 37.8 g/mol
Mass = 15.12 g
How do ocean currents affect the air temperature of Buenos Aires and Cape Town? this is for science
4. Will competition for food increase or decrease carrying
capacity?*
O A. decrease
O B. increase
pls Help ASAP - Calcium reacts with oxygen to produce calcium oxide. What mass of calcium oxide is produced when 10g of calcium burns?
Please show your working out.
Answer:
Mass = 14.025 g
Explanation:
Given data:
Mass of Ca burn = 10 g
Mass of calcium oxide produced = ?
Solution:
Chemical equation:
2Ca + O₂ → 2CaO
Number of moles of Ca:
Number of moles = mass /molar mass
Number of moles = 10 g/ 40 g/mol
Number of moles = 0.25 mol
now we will compare the moles of Ca and CaO
Ca : CaO
2 : 2
0.25 : 0.25
Mass of CaO;
Mass = number of moles × molar mass
Mass = 0.25 mol × 56.1 g/mol
Mass = 14.025 g
1.Which group of numbers can divide 54 with no remainder?
A. 1, 2, 5, 7, 12,54
B. 1, 2, 6,9, 27,54
C. 2, 4, 6, 8, 26, 54
D. 1, 2, 7, 8, 29,54
Answer:
The answer is B. 1,2,6,9,27,54
Explanation:
Which of the following statements is true about the relationship between atoms and molecules? A. Most atoms are bonded together to make a molecule. B. An atom can be seen by scientists, but a molecule cannot. C. Atoms and molecules are the same and have no differences.
Answer:
I believe the answer is A. molecules are larger than atoms so they should be visible and atoms and molecules are indeed different
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.
What is atom?
Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. Most atoms are bonded together to make a molecule. Molecules combine to form compounds.
Therefore, the correct option is option A.
To know more about atom, here:
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If you start with substance A and substance B, combine them together,
and produce a new substance C, you have witnessed a
Answer:
Chemical change
Explanation:
If you start with substance A and B and you produce C, you have witnessed a chemical change and this is a synthesis or combination reaction.
A + B → C
We know this because from the two different reactants, a new substance C has been formed.
The substance C is produced via a chemical change.
In a chemical change, new kinds of products are usually formed and the reaction is not easily reversible.
Question 1
Organisms sharing a common ancestor
Evolutionary history
A. Fossil record
B.Anatomy
C.Common ancestry
D.Evolution
Answer:
Fossil record
Explanation:
but first think about it befor you do so it could be wrong im not a computer
How many moles are in 9.07 x 10^23 atoms of sodium chloride?
Answer:
1.5 moles of sodium chloride are present.
Explanation:
Given data:
Number of moles of sodium chloride = ?
Number of atoms of sodium chloride = 9.07×10²³
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
9.07×10²³ atoms × 1 mol / 6.022 × 10²³ atoms
1.5 moles of sodium chloride are present.
CAN SOMEONE PLEASE TELL ME HOW DO I WRITE NITROGEN WITH THE "IDE" ENDING? PLEASE AND THANK YOU
Answer:
Nitride.
Explanation:
Have a good day, friend.
i really need help with this question can you guys help me
Heating up an object can cause it to
Answer:
We know that kinetic energy is one of the forms of internal energy, so the release of heat from an object causes a decrease in the average kinetic energy of its particles.
(Help if you know) What is one way land helps reduce the force of a hurricane as it moves inland?
A) land stabilizes the sediment forced on shore
B) Land filters the water forced up from the sea by the wind
C) Land acts as a bumpy surface that absorbs wind power
D) land absorbs the rainwater
How the calculation of the [OH-], pH and % ionization for 0.619 M ammonia (NH3) NH3 + H2O (liq) rightwards harpoon over leftwards harpoon NH4+ + OH- Kb = 1.8 x 10-5
Answer:
[OH⁻] = 3.34x10⁻³M; Percent ionization = 0.54%; pH = 11.52
Explanation:
Kb of the reaction:
NH3 + H2O(l) ⇄ NH4+ + OH-
Is:
Kb = 1.8x10⁻⁵ = [NH₄⁺] [OH⁻] / [NH₃]
As all NH₄⁺ and OH⁻ comes from the same source we can write:
[NH₄⁺] = [OH⁻] = X
And as [NH₃] = 0.619M
1.8x10⁻⁵ = [X] [X] / [0.619M]
1.11x10⁻⁵ = X²
3.34x10⁻³ = X = [NH₄⁺] = [OH⁻]
[OH⁻] = 3.34x10⁻³M% ionization:
[NH₄⁺] / [NH₃] * 100 = 3.34x10⁻³M / 0.619M * 100 = 0.54%
pH:
As pOH = -log [OH-]
pOH = 2.48
pH = 14 - pOH
pH = 11.52Tamara pours hot tea into a cold mug. A few moments later, she picks up the mug, and it is now warm.
Answer:The Hot tea makes the mug a hot mug
Explanation:
Answer: The thermal (heat) energy in the tea, is being transferred to the mug
8 moles Cl to grams 3
Answer: I don’t understand what your asking elaborate more
Explanation:
A sample of pure radioactive isotope is left to decay. After 40.0 days, the 1 point
sample is placed in a mass spectrometer, and it is determined that only
25% of the original isotope remains. How long is the half-life?
Answer:
6 months and 1 day
Explanation:
Differentiate between 4 H2O and H8O4
Answer:
How many atoms of hydrogen and oxygen are in 2 molecules of water? ... 7) Using complete sentences, explain the difference between the chemical ... (s) solid, (l) liquid, (g) gas, (aq) aqueous solution (dissolved in water).
Explanation:
hope this helps✌️
1. Convert 76.19g of Rb3Rn to moles
a. 0.16 moles
b. 6.28 moles
c. 36,450.06 moles
Answer: C, 36,450.06 moles
Explanation:
Molar mass=478.41
17.19gx478.41moles=36,450.06
When an atom is charged, it is called an ion. How many electrons are in O^2-?
Answer:
10 electrons
Explanation:
pls answer i need it now!! I will give brainliest to the best answer!!
Answer:
sample 2
Explanation:
hope this helps
how many grams is 5.16 mol br2?
Answer:
Mass = 824.57 g
Explanation:
Given data:
Mass of bromine = ?
Number of moles of bromine = 5.16 mol
Solution:
Formula:
Mass = number of moles × molar mass
Molar mass of bromine = 159.8 g/mol
by putting values,
Mass = 5.16 mol × 159.8 g/mol
Mass = 824.57 g
Metals bond with halogens to form colorless metal halides. During an experiment, chlorine water was added to a solution of potassium bromide. A record of the experiment is shown.
Experimental Record
Reactants Color of Reactants Color of Reactants after Mixing
cl,
Colorless solution
Deep yellow-orange colored solution is formed
KBT Colorless solution
Which of the following conclusions can be made about this chemical reaction based on the data? (1 point)
O Chlorine is more reactive than bromine.
Potassium bromide and chlorine do not react.
O Potassium metal is formed from a single replacement reaction.
O Bromine solution is colorless and is formed due to a single replacement reaction.
Answer:
O Chlorine is more reactive than bromine.
Explanation:
From this experiment we can conclude that chlorine is more reactive than bromine and it is the reason why the reaction is able to proceed.
The reaction is a single displacement reaction in which the position of an element in the activity series is very important. Since chlorine is more electronegative and highly reactive when compared to bromine, it will displace bromine from the solution of potassium bromide. So, we have product of potassium chloride and the bromide.sound travel through water at a speed of 1500 m/s. if the frequency of a sound is 1000 Hz, what is the wavelength?
Answer:
λ = 1.5 m
Explanation:
Given data:
Speed of wave = 1500 m/s
Frequency of sound = 1000 Hz
Wavelength of sound = ?
Solution:
Speed of wave = frequency × wavelength
by putting values,
1500 m/s = 1000 Hz × λ
λ = 1500 m/s / 1000 s⁻¹ (Hz = s⁻¹ )
λ = 1.5 m
Answer: 1.5
Explanation:
Well first you do
1500/ 1000= 1.5 which mean
The wavelength is 1.5
What kind of statement is," Roller coasters are the best to use of Newton's laws of motions
Answer:
An opinion.
Explanation:
In physics, Sir Isaac Newton's first law of motion is known as law of inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
The statement, "Roller coasters are the best use of Newton's laws of motions" is an opinion because it is not based on any evidence, facts or has a proof to back it up.
In English literature, an opinion is considered to be more like a claim.
A claim can be defined as a statement that is used by a writer to prove, substantiate or support an argument. Thus, a claim is an assertive statement expressed by a writer to prove that an argument is true or real.
Choose the statement below that correctly describes electrons.
a. Electrons have a positive charge and are lighter than protons
b. Electrons have a positive charge and are heavier than protons
c. Electrons have a negative charge and are heavier than protons
d. Electrons have a negative charge and are lighter than protons
Answer:
d. Electrons have a negative charge and are lighter than protons
Explanation:
The best statement that describes electrons is that electrons are negatively charged and are lighter than protons.
There are three known subatomic particles which are:
Protons which are the positively charged particles within an atom. Electrons are the negatively charged particles Neutrons do not carry any charges.The mass of the protons and neutrons are similar.
Electrons are lighter than both protons and neutrons.
How many formula units are in 2.58 moles of Caci.?
Answer:
1.55 x 10²⁴ formula units
Explanation:
Given parameters:
Number of moles of CaCl₂ = 2.58moles
Unknown:
Formula units in the compound = ?
Solution:
To solve this problem, we must understand that;
1 mole of a substance contains 6.02 x 10²³ formula units
2.58 moles will contain 2.58 x 6.02 x 10²³ formula units
= 1.55 x 10²⁴ formula units
The chemical equation below shows the photosynthesis reaction.
6CO2 + 6H2O → C6H12O6 + 6O2
A reaction uses 528 g of CO2. How many grams of water are used in this reaction?
Answer:
12
Explanation:
What are the reactants in the reaction? What are their properties? Perform a quick Internet search, if needed.
The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.
This might be the exact question so you might wanna rephrase it but good luck! :)))
A reactant is a substance that undergoes change during a chemical reaction.
A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.
There are about four types of reactions which are:
SynthesisDecompositionSingle replacementDouble replacementPlease note that your question is not complete, therefore, i would give you a general overview to help you.
Some examples of reactants include:
HydrogenSodiumChlorine, etcRead more here:
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The reaction of Pb+4 and O-2 produces the compound of
a
Pb2O2
b
PbO
c
Pb2O
d
PbO2
Answer:
Pb₂O₄
Explanation:
The given species are:
Pb⁴⁺ O²⁻
Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.
Pb⁴⁺ O²⁻
Combining power 4 2
Exchange of valencies 2 4
Now the molecular formula is Pb₂O₄
In which situation is the speed of the car constant while its velocity is changing?
A)
The car travels down a straight track at 30 m
s
m
B)
The car travels around a circular track at 30
S
The car begins from rest and accelerates to 20
S
D)
m
The car begins traveling at 30
m
and slows to 15
S
En