Answer:
the number is 7
Explanation:
"Three times" means multiply by 3
"Difference" means subtract
"Sum" means add
3(x - 7) = 23 - (3x + 2)
3x - 21 = 23 - 3x - 2
3x - 21 = 21 - 3x
6x = 42
x = 7
which of the following is is a chemical property of pure water
Answer:
Pure water has an acidity of about 7 on the pH scale. -is a chemical property of pure water. Pure water has an acidity of about 7 on the pH scale
Answer: không màu , không mùi không vị
Explanation:
Where are the most gases located on the periodic table?
Answer:
They are mostly located in group 18 (column 18), or far right
If you drip an ink drop into a cup of water and wait for a few seconds, all the water will be colored with the ink. This experiment is an example of facilitated diffusion ?
true
false
Answer:
false, it is not an example of facilitated diffusion
Answer:
TrueExplanation:
When a drop of ink added into the water gradually moves in the whole quantity of water due to this entire water turns into blue color. This is nothing but the diffusion of ink particles into the water molecules. This is because water, as well as ink molecules, are in random motion due to the motion of ink substance.
Provide the name of the compound shown below. Spelling and format counts!
CH3
NO2
NO2
Answer:
ch3:-methanide
No2:-nitrogen dioxide
thank you and mark as brainliest if u find it helpful
I need to know what is the median of the data
Answer:
The median is also the number that is halfway into the set. To find the median, the data should be arranged in order from least to greatest. If there is an even number of items in the data set, then the median is found by taking the mean (average) of the two middlemost numbers.
I hope it helps
convert 100kcals to kilojoules
Answer:
Explanation:
418.4kj is the correct answer
equal volumes 50.0 ml of 0.54897 m solution of HCL and 0.9573 M NaOH solution have an initial temperature of 18.5 degrees Celsius react in a coffee cup calorimeter the resulted Solutions records a temperature of 22.9 degrees Celsius since the solutions are mostly water the solution are assumed to have a density of 1.0 g per ml and a specific heat of 4.184 joules per gram degree celsius the heat capacity of the Colorimeter is 1.0 x 10 to power 1 joules per degrees Celsius calculate the heat and gained or released by the solution at a constant pressure in J
Answer:
Explanation:
ok
Which of the following is an example of a physical, rather than a chemical, change?
Answer: The question is not clear
Explanation:
Which one of the following compounds will be soluble in water?
A) AgCI
B) PbCO3
C) CaSO4
D) Cu(OH)2
E) LiCl
The compound that has been soluble in water will be LiCl. Thus option E is correct.
The compounds that form stable bonds in water and are easy to dissociate are soluble in water. Generally, ionic compounds are easily soluble in water.
AgCl:It has been an ionic compound, but the dissociation of AgCl will simultaneously form AgCl again making the compound insoluble in water.
[tex]\rm \bold{PbCO_3}[/tex]:It has been a covalent compound, thus it has been insoluble in water.
[tex]\rm \bold{CaSO_4}[/tex]:The compound is covalent in nature, thus it has been hard to dissociate in water.
[tex]\rm \bold{Cu(OH)_2}[/tex]:The copper in the compound has been hard to dissolve and precipitate in the solution.
LiCl:It has been an ionic compound and can be easily dissociated in the water.
Thus the compound that has been soluble in water will be LiCl. Thus option E is correct.
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A tank contains oxygen gas at 2.551 atm. What is the pressure in mmHg?
The force exerted on the container by the particles of the matter is called pressure. The tank containing oxygen gas at 2.551 atm will have a pressure of 1939 mm Hg.
What is pressure?Pressure is the property used to estimate the force experienced by the system due to the liquid or the gas held in it. The pressure of the gas can be calculated by the ideal gas and force and area.
The pressure is created due to the collision of the particles of the gases and liquids on the wall perpendicularly. It is estimated in Pascal (Pa) as the standard unit along with atm and mmHg.
It is known that 1 atm = 760 mm Hg
Given,
The pressure of oxygen gas = 2.551 atm
Using the conversion factor the pressure from atm to mm Hg is calculated as,
1 atm = 760 mm Hg
2.551 atm = (2.551 atm × 760 mm Hg) ÷ 1 atm
= 1938.76 mmHg
Therefore, 1939 mm Hg is the pressure of the oxygen gas.
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Test Question just answer random.
Answer:
U are a fool
Explanation:
Because you didn't even asked a question
Answer:
k.
Explanation:
1) What happens to the Mercury on a cool day in a thermometer??
Answer:
it's level goes down
Explanation:
because the temperature is low, so mercury level is down
Read the following statement:
Energy cannot be created or destroyed.
Does the statement describe a scientific law? (3 points)
a
No, because it universally applies to all objects
b
No, because it is not true in all circumstances
c
Yes, because it universally applies to all objects
d
Yes, because it is not true in all circumstances
Answer:
C. yes, because it is universally applies to all objects
Alex drips hydrochloric acid onto a 5.9 g piece of magnesium in a single displacement reaction. How many molecules of HCl are required? 2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)
how do you do this?
2.96 × 10²³ molecules is required if Alex drips hydrochloric acid onto a 5.9 g piece of magnesium in a single displacement reaction
According to this question, hydrochloric acid (HCl) reacts with magnesium metal (Mg) to produce magnesium chloride and hydrogen has as follows:
2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)
Based on the balanced chemical equation above; 2 moles of HCl reacts with 1 mole of Mg. Next, we convert 5.9g of Mg to moles by using the formula; mole = mass/molar massWhere; Mg = 24g/mol
mole = 5.9/24
mole = 0.246mol of Mg
If 2 moles of HCl reacts with 1 mole of Mg. 0.246 mol of Mg will react with (0.246 × 2) = 0.492mol of HClTo convert mole to number of molecules, we multiply number of moles by 6.02 × 10²³ (Avogadro's no.)
Hence, number of molecules of HCl required is 0.492mol × 6.02 × 10²³
= 2.96 × 10²³ molecules of HClHCl
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Determine the volume of H2 gas needed to react completely with 5.00L of Oz to form water
10.0L
20L
b 5L
d. 15L
Answer: 10.0 L
Explanation:
Why is ice cold water rather than room temperature or warm water used to wash the remainder of the benzoic acid out of the beaker?
As a general rule:
"Solubility of compounds decrease with the increasing of temperature" as you can see in the graph.
Also, filtration, is a chemical process where you are separating a precipitate from a solution.
Now, if you want to recover benzoic acid from an aqueous solution, the better option would be with Ice cold water because its solubility will be lower because temperature is lower producing more precipitate.
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in non- equilibrium cooling, carbon is allowed to diffuse its end position. true /false
Answer:
False because it is false
Evaluate the exponential expression (−2)6.
A general exponential expression is something like:
A^n
This means that we need to multiply the number A by itself n times.
Using that we will get (-2)^6 = 64
With that definition, we can rewrite:
(-2)^6 = (-2)*(-2)*(-2)*(-2)*(-2)*(-2)
So we just need to solve the above expression.
Also, remember the rule of signs:
(-)*(-) = (+)
We will get:
(-2)*(-2)*(-2)*(-2)*(-2)*(-2) = [(-2)*(-2)]*[(-2)*(-2)]*[(-2)*(-2)]
= 4*4*4 = 16*4 = 64
Then we got:
(-2)^6 = 64
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What is the basic unit of chemistry?
O A. The bond
O B. The atom
O C. The sun
O D. The cell
Answer:
B. The atom
Explanation:
Cells are the most basic unit of structure and the smallest unit of matter is the atom.
Answer:
B. The atom
Explanation:
yeee it was right
An individual was injected with 80 mg of inulin and 960,000 counts per min (cpm) of tritium-labeled water (3H20) to determine the volume of various body fluid compartments. After equilibration a blood sample was obtained and the plasma inulin concentration was 0.5 mg% and the plasma activity (concentration) of tritium was 20 cpm/ml. The volumes of which body compartments can be determined?
The measurement of body fluid compartments can be achieved by the dilution of chemical compounds that only circulate and disperse in the region of selected areas in the body. The dilution process is dependent on how the concentration is defined.
Given that:
the concentration of plasma insulin after equilibrium = 0.5 mg %∴
Concentration C = 0.5 mg/100
Concentration C = 0.005 mg/ml
The mass of insulin = 80 mgSince the mass amount of the chemical compound(i.e. insulin) and the concentration is known.
The volume of the body fluid compartment can be calculated as:
[tex]\mathbf{volume = \dfrac{\text{mass of the marker }}{concentration }}[/tex]
[tex]Volume = \dfrac{80 \ mg}{0.005 \ mg/ml}[/tex]
Volume = 16000 ml
Thus, it is known that insulin is generally utilized for the measurement of the extracellular fluid volume and serves as a cell impermeant marker.
As a result;
The volume of the extracellular fluid compartment is 16000 ml.
However, the tritium-labeled water is a good marker for the entire body fluid compartment due to the fact that:
its diffusion occurs throughout the entire body,it is identical to water and;the equilibrium concentration is typically easy to measure due to the radioactive characteristics of tritium.Given that:
plasma activity of tritium = 20 cpm/ml
i.e.
In 1 ml of plasma, 20 cpm of tritium is present.
As such, in 960,000 counts per min (cpm) of tritium-labeled water, the volume of the whole body compartment is:
[tex]\mathbf{= \dfrac{960000}{20} ml \plasma}[/tex]
= 48000 ml of plasma
Therefore, we can conclude that the volumes of the body compartment that can be determined are:
The volume of the extracellular fluid compartment, which is 16000 ml.The volume of the whole body compartment, which is 48000 mlLearn more about body fluid compartments here:
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MnO₄- chemical name for ALEKS
Mno4- chemical name is permanganate
You are working in a lab when radiation alarms go off. You are able to hide inside a steel cabinet, whose sides are about 1.5 inches thick, until the alarm goes off. Preliminary reports show that the radiation was weakly ionizing and negatively charged. Were you safe in the cabinet?
A. Yes, it was beta radiation and the steel was enough to block it.
B. Yes, it was alpha radiation and not harmful.
C. No, it was beta radiation and very dangerous.
D. No, it was gamma radiation and can only be blocked by a thick wall of lead.
Answer
A
Explanation:
Beta radiation is only very dangerous when it is ingested or if there is nothing in the way. The steel should protect you.
Yes, it was beta radiation and the steel was enough to block it. Hence, option A is correct.
What is beta radiation?Beta radiation is a current of electrons released at a rate exceeding the speed of light, with kinetic energy between 0.2 MeV and 3.2 MeV. Due to their lower mass which is approximately 5.5×[tex]10^{-4}[/tex] amu (9.130×[tex]10^(-24)[/tex], interactions between β-particles and the atoms of pass-through materials are much less frequent than the interactions between 5-007-particles: less than 200 ion pairs are typically formed in each centimetre of the air passage.
When we are working in a lab when radiation alarms go off and we are able to hide inside a steel cabinet, whose sides are about 1.5 inches thick, until the alarm goes off.
Preliminary reports show that the radiation was weakly ionizing and negatively charged. Yes, it was beta radiation and the steel was enough to block it.
Hence, option A is correct.
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Lead of mass 0.75kg is heated from 21°c to its melting point and continues to be heated unit it has all melted. Calculate how much energy is supplied to the lead. [Melting point of lead 372.5°c specific latent heat of fusion of lead = 23000 Jkg 'k ']
Answer:
65.5J
Explanation:
ML=Q
ML=MC(change in temperature)
0.75 X 23000 =0.75 X 351 X C
C= 65.5J
The energy supplied to the lead to melt from 21°c to its melting point is 51521 Joules.
What is the specific heat capacity?Specific heat is the amount of heat energy supplied to change the temperature of one unit mass of a substance by 1 °C. The SI unit of the specific heat capacity of a substance is J/Kg.
The mathematical expression for the specific heat capacity can be written as:
Q = mCΔT Where C is the specific heat of the substance.
The specific heat capacity depends upon the starting temperature and is an intensive characteristic of the material.
Given, the melting point of the lead T₂ = 327.5° C
The initial temperature of the lead, T₁ = 21° C
The latent heat of the lead given, L = 230000 J/Kg K
The specific heat of the lead, C = 130 J/Kg K
The heat required to melt the lead from 12°C to 327.5 °C is :
Q = m× [C × (T₂ - T₁) + L ]
Q = 0.75 × [0.130 (327.5 - 21) + 23000]
Q = 51521 J
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How many grams of magnesium chloride can be produced from 2.30 moles of chlorine gas reacting w excess magnesium Mg(s)+Cl2(g)->MgCl2(s)
The mass of magnesium chloride produced from 2.30 moles of chlorine gas is 218.99 grams.
How to calculate moles in stoichiometry?Stoichiometry refers to the study and calculation of quantitative (measurable) relationships of the reactants and products in chemical reactions.
According to this question, magnesium reacts with chlorine gas to form magnesium chloride as follows:
Mg + Cl₂ → MgCl₂
Based on the above chemical equation, 1 mole of chlorine gas forms 1 mole of magnesium chloride.
This means that 2.30 moles of chlorine gas will 2.30 moles of magnesium chloride.
Next, we convert moles of magnesium chloride to mass as follows:
molar mass of magnesium chloride = 95.211g/mol
mass of magnesium chloride = 95.211 × 2.30 = 218.99 grams.
Therefore, 218.99 grams of magnesium chloride will be formed.
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Explain the difference between temperature and thermal energy.
Explanation:
the difference between temperature and thermal energy are as follow ,
• The thermal energy, or heat, of an object is obtained by adding up the kinetic energy of all the molecules within it. Temperature is the average kinetic energy of the molecules.
s-Block compounds give a characteristic flame colour in the flame test. Based on this, can you give one use of s-block compounds?
Answer:
Lithium is used in making electrochemical cells.
how hydrogen chloride gas is prepared on labrotary by conc sulpheric acid
Answer:
It is prepared small amounts of hydrogen cloride for uses in the lab.
It can be "generated in an HCl generator by dehydrating hydrochloric acid with either sulfuric acid or anhydrous calcium chloride."
Name the following alkane molecule:
CH3
CH3CCH3
CH3
A. 2-ethylpropane
B. 2-dimethylpropane
C. 2,2-dimethylpropane
not 100% sure but I think its C
The correct name for the given alkane molecule is 2,2-dimethylpropane. (Option C)
The given alkane molecule is composed of three carbon atoms. The central carbon atom is bonded to two methyl groups (CH₃) on either side. This results in a branched structure where the methyl groups are attached to the same carbon atom.
According to the rules of IUPAC nomenclature, the prefix "2,2-" indicates that the methyl groups are attached to the second carbon atom in the main chain. The parent chain, which consists of three carbon atoms, is named propane. Since there are two identical methyl groups attached to the second carbon atom, the compound is named 2,2-dimethylpropane.
Hence, the name of the given alkane molecule is 2,2-dimethylpropane.
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HELP! How is the mass number of an atom calculated?
A - total number of electrons
B - total number of protons
C - protons plus neutrons
D - electrons plus neutrons
True or false? The smaller the temperature differences, the stronger the wind will be.
Answer:
true because whenever the temperature drops it gets colder
