Answer:
Cr ^ 3 +
Explanation:
Recordemos que el número atómico es el número de protones en el núcleo del átomo. También corresponde al número de electrones en el átomo neutro.
Dado que el número de protones es 24, entonces el elemento debe ser cromo.
Si hay 21 electrones presentes, entonces se deben haber perdido 3 electrones para dar Cr ^ 3 +.
25.Which of the following reaction will not take place?
A. Zn+ FeSO4 → ZnSO4 + Fe
C. Fe + NiSO4 → FeSO4 + Ni
B. 2Al + 3MgSO4→ Al2(SO4)3 + 3Mg D.
Cu + 2AgNO3 → Cu(NO3)2 + 2Ag
Answer:
B
Explanation:
because Mg is stronger than Al
A 240g hydrated sodium sulphide contains 162g of water of crystallisation. What is the correct molecular formula for this compound?
What is the answer and working
Answer:
Explanation:
First of all, 1 mol of Sodium Sulphide has molecular mass of
S = 32
Na2 = 2*23 = 46
The formula of NaS is actually Na2S. It's molecular mass = 78
How many grams of Na2S are present
Grams present = 240 - 162 = 78 which is exactly 1 mol.
The remainder is water.
The molecular mass of water = 2 + 16 = 18
162 grams of water = 162/18 = 9 mols of water.
So the correct formula is Na2S*9H20
Which of the following results in a decrease in the entropy?
Heating ice
Increasing mass
Cooling a liquid
Dissolving salt in water
Answer:
cooling a liquid
Explanation:
Temperature is lowered and the energy of molecules, and therefore number of available configuration , is lowered
The thermal energy present in the system for the product formation is entropy. Cooling a liquid can decrease the entropy of the thermodynamic system. Thus, option C is correct.
What is entropy?Entropy is the energy and the heat present in the reactant of the thermodynamic system that is associated with the randomness and disorder of the particle matter in the reaction system.
Entropy is dependent on factors like dissolution, temperature, randomness, kinetic energy, etc. The entropy increases with an increase in the dissolution and tempearture.
The process of cooling liquid lowers the temperature which in turn decreases the kinetic energy and randomness of the molecules and at last, the entropy decreases.
Therefore, the cooling of the liquid decreases the entropy.
Learn more about entropy here:
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What is the density of ammonia (NH3) at 273 K and 1.00 atm?
A - 0.7601 g/L
B - 0.982 g/L
C - 1.23 g/L
D - 2.43 g/L
Answer:
0.7602 g/L
Explanation:
We'll begin by calculating the molar mass of NH₃. This can be obtained as follow:
Molar mass of NH₃ = 14.01 + (3×1.01)
= 14.01 + 3.03
= 17.04 g/mol
Finally, we shall determine the density of ammonia, NH₃. This can be obtained as follow:
Temperature (T) = 273 K
Pressure (P) = 1 atm
Molar mass of NH₃ (M) = 17.04 g/mol
Gas constant (R) = 0.0821 atm.L/Kmol
Density (D) =?
D = PM / RT
D = (1 × 17.04) / (0.0821 × 273)
D = 17.04 / 22.4133
D = 0.7602 g/L
Answer:
It is A
Explanation:
3. Determine the pH value for calcium hydroxide, Ca(OH), with concentration of
0.05 mol dm3. [pH + pOH = 14).
Explanation:
Ca(OH) is a base
pOH = -Log[OH]
[OH] = 0.05
pOH = -Log(0.05)
pOH = 1.3
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 2
pH = 12.7
Which of the following units are commonly used in chemistry? A Kelvin b ampere c fluid ounce d kilogram
Explanation:
your answer is Kelvin because it is the SI unit of temperature
A small gap in skit in railway track why
Answer:
To reduce the bending of the railway
Explanation:
During summer(heat) metals tend to expand in size. The skits/gaps are present in the railway so that the metal could expand without causing bending of the railway track.
Which option explains why this amino acid can act
both an acid and a base?
(1 point)
It contains both an amino functional group and a carboxyl functional group. In a solution, the amino group can
increase acidity, while the carboxyl group can decrease acidity
It contains both an amino functional group and a methyl functional group. In a solution, the amino group can
increase acidity, while the methyl group can decrease acidity
It contains both an amino functional group and a carboxyl functional group. In a solution, the amino group can
decrease acidity, while the carboxyl group can increase acidity
It contains both an amino functional group and a methyl functional group. In a solution, the amino group can
decrease acidity, while the methyl group can increase acidity
The correct answer is: It contains both an amino functional group and a carboxyl functional group. In a solution, the amino group can
decrease acidity, while the carboxyl group can increase acidity.
The carboxyl functional group is acidic while the amine group is basic.
In an amino acid, there are two functional groups;
The amine groupThe carboxyl groupThe carboxyl functional group is acidic because it contains a replaceable or ionizable hydrogen ion. The amine group on the other hand is capable of accepting a proton hence it is basic.
Therefore, In a solution, the amine group can decrease acidity, while the carboxyl group can increase acidity.
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How many moles are there in 2.3 x 1024 atoms of
sulfur?
Explanation:
The steps given in the question are incorrect.
Step 1 should be convert atoms to moles (n). Step 2 should be convert moles (n) to mass (m).
Step 1
Use dimensional analysis to convert the number of atoms to moles.
1 mole atoms = 6.022 × 10²³ atoms
n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms) = 3.8193 mol Ag
Step 2
Convert the moles of Ag to mass.
mass (m) = moles (n) × molar mass (M)
n(Ag) = 3.8193 mol Ag
M(Ag) = atomic weight on the periodic table in g/mol = 107.868 g Ag/mol Ag
m(Ag) = 3.8193 mol × 107.868 g/mol = 412 g Ag = 410 g Ag rounded to two significant figures
The mass of 2.3 × 10²⁴ Ag atoms is approximately 410 g.
Answer:
[tex]\boxed {\boxed {\sf 3.8 \ moles \ of \ sulfur}}[/tex]
Explanation:
We are asked to convert a number of atoms to moles.
We can convert atoms to moles using Avogadro's Number, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of sulfur. There are 6.022 ×10²³ atoms of sulfur in 1 mole of sulfur.
We use dimensional analysis to convert atoms to moles. This involves setting up ratios. Use Avogadro's Number and the underlined information to make a ratio.
[tex]\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]
We are converting 2.3 ×10²⁴ atoms of sulfur to moles, so we multiply by this value.
[tex]2.3 \times 10^{24} \ atoms \ S *\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]
Flip the ratio. It is equivalent, but it allows the units of atoms of sulfur to cancel.
[tex]2.3 \times 10^{24} \ atoms \ S *\frac {1 \ mol \ S}{6.022 \times 10^{23} \ atoms \ S}[/tex]
[tex]2.3 \times 10^{24} *\frac {1 \ mol \ S}{6.022 \times 10^{23} }[/tex]
[tex]\frac {2.3 \times 10^{24} }{6.022 \times 10^{23} } \ mol \ S[/tex]
[tex]3.819329127 \ mol \ S[/tex]
The original measurement of atoms (2.3 ×10²⁴) has 2 significant figures, so our answer must have the same. For the number we calculated that is the tenths place. The 1 in the hundredths place to the right (3.819329127) tells us to leave the 8 in the tenths place (3.819329127).
[tex]3.8 \ mol \ S[/tex]
2.3 ×10²⁴ atoms of sulfur is equal to approximately 3.8 moles of sulfur.
For the reaction 2HNO3 + Mg(OH)2 + Mg(NO3)2 + 2H20, how many
grams of magnesium nitrate are produced from 3.54 mol of nitric
acid, HNO3?
O a. 220
O b. 263
O c. 1050
O d. 175
Answer:
B
Explanation:
to make 400 gram solution with a mass by a mass concentration of 6 % how much salt and water you need to mix
Answer:
[tex]400 \div 6 \\ \\ [/tex]
Do cycloalkanes easily take part in addition reactions?
Answer:
The reactions of the cycloalkanes are generally just the same as the alkanes, with the exception of the very small ones - particularly cyclopropane. ... In the absence of UV light, cyclopropane can undergo addition reactions in which the ring is broken
would Nitrogen Dioxide be ionic or covalent
Explanation:
The nitrogen dioxide is a covalent compound where one nitrogen is the central atom which is bonded to two oxygen atoms, where one oxygen atom is bonded by a single bond and other oxygen atom by a double bond.
Answer: colavent
Explanation:
What is the atomic number of the atom in the diagram above please ?
Answer:
5
Explanation:
The atomic number is the number of protons in an atom. Protons are the positively charged particles in the nucleus. The number of protons define the identity of an element. An element with 5 protons is Boron, no matter how many neutrons may be present.
The atomic number of the atom shown in the diagram is 5.
What is the atomic number?The atomic number of an element refers to the number of protons in the nucleus of its atoms. It uniquely identifies an element and determines its chemical properties.
In the diagram, there are 5 proton numbers in the nucleus of the atom. In other words, this means that the atomic number of the atom is 5.
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why hydrogen and oxygen all around us dows not form water
Answer:together doesn't make water
Explanation:
together doesn't make water
what is bonding in chemistry
Explanation:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
if you want please give me brainliest and sir
Answer:
Check Down
Explanation:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bond.
Out of a box of 46 matches, 22 lit on the first strike. What percentage of the matches in the box did not light on the first strike?
Answer: 52.17%
Explanation:
Number of matches in the box = 46
Number of matches that lit on the first strike = 22
Number of matches that did not light on the first strike = 46 - 22 = 24
Therefore, the percentage of the matches in the box did not light on the first strike will be:
= (Number of matches that did not light on the first strike / Number of matches in the box) × 100
= 24/46 × 100
= 52.17%
Therefore, the percentage of the matches in the box that did not light on the first strike is 52.17%.
PLZ HELP ME WITH MY WORK
Answer:
neutrons should be added with the protons
Which is the best term to use when describing the energy of motion? chemical kinetic potential thermal
Answer:
Kinetic energy
Explanation:
Kinetic energy is the energy associated with an object's motion. It is mass and velocity dependent by a directly proportional relationship.
Potential energy is the energy associated with an object's position.
Thermal energy is the energy associated with heat addition or withdrawal.
Kinetic energy is the energy that a body possesses because of its movement, that is, it is the energy that arises when objects are in motion.
What is kinetic energy?It is that energy that a body or system possesses due to its movement.The amount of work done by all the forces acting on a body with a given mass, depends on the said mass and the speed of the body.Therefore, we can conclude that kinetic energy is the energy produced by its movements that depends on its mass and speed.
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what are two consents in this experiment
The number of cricket chirps
The temperature of each container
The kind of containers used
The number of crickets in each container
Answer:
the number of crickets in each container
Explanation:
to participate in the experiment you will have to know the crickets in the container
Làm thế nào để tắt mỗi chất ra khỏi hỗn hợp gồm bột nhôm bột sắt và bột gỗ?
Answer:
Dùng nam chân hút đc bột sắt ra khỏi hỗn hợp
Bột gỗ và bột nhôm thì bột gỗ tan trong nước còn bột nhôm thì không
Explanation:
Nice !PLZ HELP ME WITH MY WORK
Answer:High density
Explanation:
The metal doesn't remains gas at room tempreture, it doesn't have brittleness property and it is not poor conductor of electricity .But, it has high density .
Hope, it would be correct.
Which statement best describes the destiny of an atoms nucleus?
Answer:
The answer would be: An atom’s nucleus occupies very little of the atom’s volume but contains most of its mass
Explanation:
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.
Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud.
Refer to https://en.wikipedia.org/wiki/Atomic_nucleus for further understanding
A piece of unknown metal with mass 68.6 g is heated to an initial temperature of 100 °C and dropped into 8.4 g of water (with an initial temperature of 20 °C) in a calorimeter. The final temperature of the system is 52.1°C. The specific heat of water is 4.184 J/g*⁰C. What is the specific heat of the metal?
0.171
0.343
1.717
3.433
Answer:
1.717
Explanation:
As the mass of the nucleus increases, what happens to the ratio of neutrons to protons in stable isotopes? A. The neutron:proton ratio decreases. B. The neutron:proton ratio increases. C. The neutron:proton ratio remains 1:1. D. The neutron:proton ratio remains 1.5:1.
Can Some One Please Help Me
Answer:
12 g
Explanation:
From the question given above, the following data were:
Number of atoms = 6.02×10²³ atoms
Mass of ₆C¹² =?
From Avogadro's hypothesis,
1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole of ₆C¹² also contains 6.02×10²³ atoms i.e
1 mole of ₆C¹² = 6.02×10²³ atoms
Recall
From the period,
1 mole of ₆C¹² = 12 g
Thus,
12 g of ₆C¹² = 6.02×10²³ atoms
Therefore, 12 g of ₆C¹² contains 6.02×10²³ atoms
Determine the type of alcohol corresponding to each given description or name. 3-ethyl-3-pentanol Choose... An alcohol with two other carbons attached to the carbon with the hydroxyl group Choose... An alcohol with three other carbons attached to the carbon with the hydroxyl group Choose... 1-pentanol Choose... 2-hexanol Choose... An alcohol with one other carbon attached to the carbon with the hydroxyl group Choose...
Answer:
An alcohol with three other carbons attached to the carbon with the hydroxyl group
An alcohol with two other carbons attached to the carbon with the hydroxyl group
Explanation:
If we look at 3-ethyl-3-pentanol, we will discover that the compound is a tertiary alcohol. That is, the carbon atom bearing the hydroxyl group is attached to three other carbon atoms as gown in image 1 attached.
For 2-hexanol, the carbon atom bearing the hydroxyl group is attached to two other carbon atoms hence the alcohol is a secondary alcohol. The compound is shown in image 2 attached.
What does the reducing agent do in a redox reaction? (A.P.E.X)
Answer:
The reducing agent donates electron to the oxidizing agent and gets oxidized itself
Explanation:
In an oxidation-reduction reaction, also known as REDOX reaction, one of the reactants is called OXIDIZING AGENT while the other is called REDUCING AGENT. The reducing agent is called so because it reduces another substance in the reaction.
It reduces another atom/ion by donating electrons to that atom, hence, getting oxidized itself in the process. For example, in the following reaction:
H2 + F2 → 2HF
Fluorine is getting oxidized from -2 to 0 by donating electrons to H and reducing it from +2 to 0.
Answer:
Reduces another atom
Explanation:
:)
iron filings react with sulphuric acid to produce hydrogen and iron(II) sulphate
Answer:
is this true and false? then its true
Explanation:
Answer:
Fe(s) + H2SO4 (aq) ---> FeSO4 (s) + H2 (g)
Explanation:
What amount of SeC16 is needed to produce 4.45 mol of chlorine gas in the
reaction Seclo +0 218) —SeO, +3Cl2te)?
2.85 mol
0.95 mol
5.70 mol
8.55 mol
1.49 mol
Answer:
1.48 moles of SeCl6 are needed
Explanation:
Based on the reaction:
SeCl6 + O2 → SeO2 + 3Cl2
1 mole of SeCl6 reacts producing 3 moles of Cl2.
To solve this question we need to use the conversion factor:
1mol SeCl6 = 3mol Cl2
As we want to produce 4.45 moles of Cl2, we need:
4.45 mol Cl2 * (1mol SeCl6 / 3mol Cl2) =
1.48 moles of SeCl6 are needed