Answer:
1. 3x-3=18
Value of x=7
2. 4x-5=23
value of x=7
Answer:
b 7 for one
a 3 for two
Explanation:
for tour substances.
Melting and Boiling
Points of Substances
Name
Melting Boiling
Point (°C) Point (°C)
-101
-35
-210
- 196
Chlorine
Nitrogen
Oxygen
Hydrogen
-218
183
-259
-253
Which substance is a solid at -200°C?
Which part of the immune system can be "trained" using vaccines?
How many atoms are in a sample containing 4.000 moles of carbon?
A)6.022 x 10
23
atoms
B)2.408 x 10
24
atoms
O
24
C)7.233 x 10 atoms
D)2.893 x 10
25
atoms
Answer:
c I think but that's only what i think
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of atoms/molecules/ formula units of carbon= number of moles of carbon × 6.022×10²³
number of moles of carbon= 4 moles
substituting all the given values in the above equation, we get
number of atoms/molecules/ formula units of carbon= 4 × 6.022×10²³
number of atoms/molecules/ formula units of carbon=2.4088×10²⁴ atoms of carbon
There are 2.4088×10²⁴ atoms of carbon
Therefore, 24.088×10²³ atoms of carbon are in sample containing 4.000 moles of carbon. The correct option is option B.
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1.86 g of ethanol reacts with 10.0 g of oxygen. What is the total volume of gas present (in L) after the reaction is complete, assuming the reaction takes place at 1.00 atm and 25oC?
Answer:
See explanation
Explanation:
The equation of the reaction is;
C 2 H 6 O(l) + 3 O 2 (g) → 2 CO 2 ( g ) + 3 H 2 O(l )
Next we have to determine the limiting reactant, this reactant gives the least number of moles of product.
Number of moles of C 2 H 6 O = mass/molar mass = 1.86g/ 46.07 g/mol = 0.04 mols
From the equation;
1 mol of ethanol yields 2 mols of CO2
0.04 moles of ethanol yields 0.04 * 2/1 = 0.08 mols of CO2
For water;
1 mol of ethanol yields 3 mols of water
0.04 moles of ethanol yields 3 * 0.04/1 = 0.12 mols of water
Also;
Number of moles of oxygen= 10g/32g/mol = 0.31 moles
3mols of O2 yields 2 moles of CO2
0.31 moles of O2 yields 0.31 * 2/3 = 0.21 moles of CO2
For water;
3 moles of O2 yields 3 moles of water
0.31 moles of O2 yields 0.31 * 3/3 = 0.31 moles of water
Hence ethanol is the limiting reactant.
From PV=nRT
Volume of CO2 is;
V = nRT/P
V = 0.08 * 0.082 *298/1 = 1.95 L
Volume of water;
V = nRT/P
V= 0.12 * 0.082 * 298/1
V= 2.93 L
Total volume of gases after reaction = 1.95 L + 2.93 L = 4.88 L
An object with a
mass of 7 g and a
volume of 10 mL is
most likely what
substance?
Answer:
Ethanol
Explanation:
Given parameters:
Mass of the object = 7g
volume of the object = 10mL
Unknown:
The kind of substance it is = ?
Solution:
Since from the parameters, we can determine the density of the object. Density is an intensive property of substances.
So, we simply find the density and check a density table for the type of substance it is.
Density is the mass per unit volume.
Density = [tex]\frac{mass}{volume}[/tex]
Let us take the volume to cm³;
10mL = 10cm³
Density = [tex]\frac{7}{10}[/tex] = 0.7g/cm³
This is most likely ethanol
What is immigration and emigration
Answer:
well for me I think
Explanation:
immigration is the movement which involves an individual moving from a present place to another environment
That is going out
WHILE
Emigration is the process where a person comes into a particular environment
That means coming in
you weigh out 43.9 g of potassium (K). How many moles of potassium did you weigh? How many atoms?
Answer:
1.12 moles of potassium
6.76x10²³ atoms of potassium
Explanation:
In order to convert g of potassium to moles, we need to use its molar mass (which we can find via the periodic table):
Molar Mass of K = 39.09 g/mol43.9 g K ÷ 39.09 g/mol = 1.12 mol KThen, to convert moles into atoms, we use Avogadro's number (6.023x10²³ atoms per mole):
1.12 mol K * 6.023x10²³[tex]\frac{atoms}{mol}[/tex] = 6.76x10²³ K atomsall of the following are properties of ionic compounds except:
A. Ionic compounds have low melting points,
B. Ionic compounds have high boiling points
C. Ionic compounds conduct electricity when dissolved in water
D. Ionic compounds are solid at room temperature
Answer:
A
Explanation:
They have generally high melting point compared to covalent compounds because they are formed by electrostatic force of attraction between two opposite charge is not easy to melt them in low melting point.
Ionic compounds have high melting and boiling points. Therefore, option A is not a property of ionic compound. Hence, option A is the correct answer.
Ionic compounds are neutral compounds. Ionic compounds are formed from cations and anions. Positively charged ion (cation) and negatively charged ion (anion) are held together with strong ionic bond. Some main properties of ionic compounds are,
High melting point and boiling pointsHave definite size and shapeConduct electricity in molten statesoluble in water and not soluble in organic solventsThus, we can conclude ionic compounds have high melting and boiling points. Hence, option A is the correct answer.
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Which of the physical processes below result in the formation of metamorphic rocks
i dont see any processes below
Answer:
Heat and pressure
Explanation:
got it on study island
How does adding a lone pair affect the position of existing atoms and lone pairs
Answer:
How does adding a lone pair affect the position of existing atoms and lone pairs? It decreases the angles between the atoms - the atoms are moving closer because they are being repelled further away from the lone pairs then they are from the other atoms
Explanation:
hope it helps!
How many protons, neutrons, and electrons does 35/17 Cl ^ 1- have?
Answer:
In accordance to the pic
The number of protons in Cl-35 is 17 and the number of neutrons is 18. The number of Cl is 17 whereas the chloride ion Cl⁻ have 18 electrons.
What is chlorine?Chlorine is 17th element in periodic table. Cl is includes in the 17th group of p -block. Cl contains 7 valence electrons and it needs one more electron to attain complete configuration. It is highly electronegative and will easily gain an electron to achieve octet.
Atoms in neutral state have equal number of electrons and protons and this number is equal to the atomic number. The mass number is the sum of number of protins and neutrons.
The atomic number of Cl is 17. Hence the number of protons is 17 and the mass number is 35. So that number of neutrons is 35 - 7 =18. When Cl gains an electron it forms the anion Cl⁻. Hence, the number of electrons in Cl⁻ is 18.
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Calculate the energies of the n=2 and n=3 states of the hydrogen atom in Joules per
atom
Answer:
See Explanation
Explanation:
Positional Energy for electron as function of principle energy level (n)
=> Eₙ = -A/n²; A = 2.18x10⁻¹⁸J
Positional Energy for electron in n=2 => E₂ = -2.18x10⁻¹⁸/(2)² = -5.45x10⁻¹⁹J
Positional Energy for electron in n=3 => E₃ = -2.18x10⁻¹⁸/(3)² = -2.42x10⁻¹⁹J
ΔE(n=3→2) = -5.45x10⁻¹⁹J - (-2.42x10⁻¹⁹J) = -3.03x10⁻¹⁹J
What happens to molecular energy(heat) in water when water vapor becomes a liquid?
Group of answer choices
Water vapor gives up heat energy.
Water vapor absorbs heat energy.
As water's mass increases it absorbs energy.
Water vapor retains the same heat energy.
Answer:
Water vapor retains the same heat energy.
Answer:
water vapor gives up heat energy.
Explanation:
Took a quiz and got it right
Explain how atomic
radius, valence electrons
and effect nuclear charge
creates the trend for metal
reactivity.
Answer:A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital.
Answer:
A higher effective nuclear charge causes greater attractions to the electrons, pulling the electron cloud closer to the nucleus which results in a smaller atomic radius. Down a group, the number of energy levels increases, so there is a greater distance between the nucleus and the outermost orbital.Explanation:
Law of Universal Gravitation (what factors affect gravity and how?)
Explanation:
Hey there!
According to the law of gravitation, the factors that affects the gravity are:
Mass of the heavenly bodies.Distance from the centre of the body to next body.Mass of heavenly bodies:The mass of heavenly bodies affect the gravity. We know that gravity is directly proportional to the mass of heavenly bodies. so, when the mass is more there is more gravity and where there is less mass there is less gravity.
Distance from the centre of the body to next body: It is one of the factor to influence gravity. When there is more distance there is less gravity and where there is distance more force is there. Is means gravity is inversely proportional to the distance between the bodies.
Hope it helps...
d = 7 V = 950 cm M = 95 g
0.1 g/cm3
0.1 cm3
90,250 g
90,250 g/cm3
Answer:
daddy chill
Explanation:
name the group and period of an element having atomic number 21
Answer:
The element in question here is Scandium, with an atomic number of 21. It is situated in Group 3 and Period 4 of the Periodic Table.
Explanation:
Hope this helped!
PLEASEEE HELP ?!?!?!
which of the following processes provide evidence of the particulate nature of matter
I. Diffusion
II. Filtration
III. Osmosis
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Answer:
B
Explanation:
I think the answer is Diffusion and Osmosis
The processes that provide evidence of the particulate nature of matter would be diffusion and osmosis.
Matter is defined as anything with mass/weight and able to occupy space. Matters could be molecules of solid, liquid, or gases. The molecules of each category of matter have their specific characteristics.Molecules of liquids and gases are able to diffuse. Diffusion is defined as the movement of molecules from the region of high concentration to the region of low concentration. Molecules of solids in the dissolved form are also able to diffuse. Water molecules are also able to move from the region of high to the region of low water potentials by osmosis in the presence of a semi-permeable membrane.Thus, both diffusion and osmosis back up the particulate nature of matter.
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What is the name of the compound with the formula LiNO3?
Answer:
Lithium nitrate
Explanation:
Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate).
How do you draw the Lewis structure of compound with an ionic bond
Answer:
[Na]^+ [Cl]^-
Explanation:
Lets say its sodium, its number of electrons is 11, but when its stable (an ion), it is 10. and chloride, number of electrons is 17, but when its stable (an ion) it is 18. So the lewis structure for that is, remember with the straight brackets (not sure what it's called, but you know what I mean I guess) its this one: [ ]
Sodium will be + because it has more protons (11-10 = +1), and chloride will be - because it gained an electron, so has more electrons than protons (17-18 = -1)
So the lewis structure would be:
[Na]^+ for sodium
and
[Cl]^- for chlorine
Sodium chloride:
[Na]^+ [Cl]^-
Also just to add, only 1 of each atom (Na and Cl) was needed for the bonding, but if let's say example; 2 Cl was needed to bond with sodium, there would be 2 Cl (same) and 1 Na.
Will give brainliest
Answer:
C
Explanation:
The concept behind, is mole ratio of Al:FeO
Describe the reaction of zinc with sulphuric acid
Answer:
Zinc reacts with dilute sulphuric acid to produce hydrogen gas (H2) and zinc sulphate. This is an example of displacement reaction of a non-metal by a metal. ... ZnSO4 is different in chemical composition and chemical properties than Zn and H2SO4 so it is a chemical change.
Answer:
Reaction of Zinc with Dilute Sulphuric Acid
Zinc is more reactive than hydrogen and it displaces hydrogen from dilute acids. Zinc reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas is evolved. This is a single displacement reaction of a non-metal by a metal. ... So, this reaction is a chemical change.
Balance this equation.
_Mg +_Cl2 -->_MgCl2
Answer:
1Mg + 1Cl2 = 1MgCl2
Explanation:
Hi! When balancing an equation, you want to make sure that there are equal amounts of each element on both sides. When looking at the equation that you provided in the question, look and count how many of each element are on each side. I can see that there is 1 Mg ion on the left and 1 Mg ion on the right. There are also 2 Cl ions on the left and 2 Cl ions on the right. Because they are already equal, the coefficients in front of each compound will be 1. If the amounts were different on each side, that is when you would need to add different coefficients.
Hope this helps! Let me know if you have any other questions about this!
Which type of energy is the tree changing the light energy into?
Answer: Chemical energy
Explanation: In this case plants convert light energy (1) into chemical energy, (in molecular bonds), through a process known as photosynthesis. Most of this energy is stored in compounds called carbohydrates. The plants convert a tiny amount of the light they receive into food energy.
Answer:
chemical energy
In this case plants convert light energy into chemical energy, (in molecular bonds), through a process known as photosynthesis. Most of this energy is stored in compounds called carbohydrates. The plants convert a tiny amount of the light they receive into food energy.
Explanation:
The percent ionization of a 0.350 M HC,H,O2 solution. Ka(HC2H302)
Answer:
The answer is 56
Explanation:
i need points
15
Question 56 (1 point)
What is the name of the compound with the chemical formula SnSnO3?
Answer: sodium sulfite
Explanation:
When naming covalent compound both the first and second element in the fomula always receive
a prefix to represent the number of each element present in the chemical formula.
Answer:
Yes.
Explanation:
Yes, both the first and second element in the formula of covalent compound always receive a prefix to represent the number of each element present in the formula in order to show the percentage or proportion of each element in the formula of covalent compound. Prefix refers to addition of word, letter, or number at the beginning of something so here number placed in front of element indicates the prefix.
True or False: Most metals are found to occur naturally in their uncombined states.
Answer:
I think it's true. But I'm not sure
Answer:
True
Explanation:
Which is a pure substance?
They are chemically bonded together.
They can be classified as pure substances.
They have fixed ratios between their components.
They can be separated by physical processes.
Answer: C. They have fixed ratios between their components.
How can the rate of a reaction be increased?
(A) decreasing the amount of reactants
(B) having more surface area
(C) diluting a solution
(D) lowering the temperature
Explanation:
Rate of reaction can be increased by having more surface area.
Therefore,
Option B is correct✔
Answer:
b
Explanation: