Answer:
0.009871
Explanation:
[tex] 9.871\times 10^{-3} = 0.009871[/tex]
Answer:
.009871
Explanation:
What is the PRECAUTION for an Irritant?
Lab Safety Rule #3 says to always add acids or bases to the solvent and NEVER the other way around true or false?
Answer:
true
Explanation:
The standard laboratory rule is to always add acids or bases to solvent and not the other way round.
The dissolution of concentrated acids/bases in solvents (water) generates heat energy. Thus, if the solvent is added to them, a layer of hot weak acid or base will be formed and this will boil and spray around, causing an explosion.
On the other hand, if acid/base is added to solvents, they flow into the solvents and get diluted immediately without any boiling taking place. Hence, it is safe to add acid/base to solvents and not the other way round.
Which of the following processes is exothermic? Group of answer choices Allowing meat to thaw after taking it out of the freezer Popsicle melting on a warm summer day Boiling water in a beaker to convert it to steam Rolling a ball up a hill Reacting hydrogen and oxygen gases to make water
Answer:
Reacting hydrogen and oxygen gases to make water
Explanation:
Exothermic means that energy is released into the environment, so let's go through the process of elimination.
Allowing meat to thaw after taking it out of the freezer - NO it is endothermic, and takes energy/heat from the environment to thaw.
Popsicle melting on a warm summer day - NO also endothermic, the opposite of exothermic.
Boiling water in a beaker to convert it to steam - NO because we need to add heat, so it doesn't release any energy.
Rolling a ball up a hill - NO, for a ball to roll up a hill, it needs energy from something else, so it's not exothermic.
Reacting hydrogen and oxygen gases to make water - YES this reaction makes new bonds, which releases energy, so this is exothermic.
Among the following choices reacting hydrogen and oxygen gases to make water is an exothermic reaction as it releases energy as new bonds are formed.
What is an exothermic reaction?An exothermic reaction is defined as a chemical reaction which involves release of energy in the form of light,heat .In these reactions, energy is transferred from system to surroundings rather than taking energy from surroundings into system as in endothermic reactions.
In an exothermic reaction,change in enthalpy is negative.Therefore, it can be inferred that net amount of energy which is required to start the exothermic reaction is less than the net amount which is released by the reaction.
Examples of exothermic reactions are combustion reactions, detonation of nitroglycerin , neutralization reactions and nuclear fission.
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Describe the reaction of an acid with an alkali.?
Your question has been heard loud and clear.
The reaction of an acid with an alkali is neutralization reaction. It is a neutralization reaction because , they both neutralize each other (means it makes them chemically inactive after reacting) and produce a salt , and maybe water too.
An example: hydrochloric acid + sodium hydroxide → sodium chloride + water
Thank you
it will neutralise because if you add both of them together with a matching Ph such as 5 and 9 equally then it will neutralise and have a Ph of 7
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It requires work to _____. A. stretch a spring only B. compress a spring only C. stretch or compress a spring
Answer:
C.
Explanation:
It requires work to stretch or compress a spring.
Answer:the answer is c
Explanation: i say that because with work you can do both of those things
When a substance's particles are packed together tightly and have a definite shape and
volume...it is said to be in what state?
solid
gas
plasma
liquid
Answer:
solid
Explanation:
Why does science need to.change its view on ideas overtime?
Explanation:
A scientific idea is an explanation for how something works, or the truth about some aspect of the world, that was figured out using the scientific process. ... Scientific ideas change over time as the evidence improves. The more experiments they do , and the more data they collect, the better the scientific ideas become.
Consider the reaction of 2.5 grams of Li (s) reacting with 0.5 grams of N2 (g) to produce Li3N (s). A) How many total grams of Li3 N (s) would be produced? B) Which of the starting elements is the limiting reagent, and how many grams of the non-limiting reagent remain after the reaction has completed?
Answer:
A) The amount in grams of Li₃N produced is 1.243 g
B) N₂, is the limiting reagent
The mass of the non-limiting reagent, Li, remaining after the reaction is completed is 1.757 g
Explanation:
The given parameters are;
The mass of Li(s) = 2.5 grams
The mass of N₂ (g) = 0.5 grams
The chemical equation for the reaction can be presented as follows;
6 Li (s) + N₂ (g) → 2 Li₃N
Therefore, 6 moles of Li reacts with 1 mole of N₂ to produce 2 moles of Li₃N
The molar mass of Li = 6.941 g/mol
The molar mass of N₂ = 28.0134 g/mol
The number of moles of a reactant or product, n is given by the relation;
n = Mass of substance/(Molar mass of the substance)
For lithium, Li, n = 2.5/6.941 = 0.3602 moles
For Nitrogen gas, N₂, n = 0.5/28.0134 = 0.01785 moles
A) Given that 1 mole of N₂ to produces 2 moles of Li₃N
0.01785 moles of N₂ will produces 2×0.01785 = 0.0357 moles of Li₃N
The molar mass of Li₃N = 34.83 g/mol
The mass of Li₃N = 34.83 g/mol × 0.0357 moles = 1.243 g
B) 6 moles of Li reacts with 1 mole of N₂ to produce 2 moles of Li₃N
0.3602 moles will reacts with 1/6×0.3602 = 0.06003 mole of N₂
Therefore, N₂, is the limiting reagent and we have;
0.01785 moles of N₂ will react with 6×0.01785 = 0.1071 moles of Li
The number of of moles of Li left = 0.3602 - 0.1071 =0.2531 moles
The mass of lithium left = 0.2531 moles × 6.941 g/mol = 1.757 g
The mass of lithium remaining after the reaction is completed = 1.757 g.
Undulation in sandy material is called
cross-beds
ripple marks
mud cracks
O fossils
Answer:
ripple marks
Explanation:
Undulation is defined as the to and fro wavelike motion in a fluid or elastic medium.
Undulation in sandy material is called ripple marks because ripple marks are the sediments of rocks that show wavy structure at its surface due to agitation by water and wind.
Hence, the correct answer is "ripple marks".
Levi decides to examine the effect of fertilizer on the growth of tomato plants. He chooses four plants for his experiment and applies varying amounts of fertilizer to three of them. He does not apply fertilizer to one plant. Over a 15-day period, the plants receive fertilizer on Days 1, 4, 7, 10, and 13. Levi measures the height of all of his plants with a meter stick on days 3, 6, 9, 12, and 15. He also makes sure to hold all experimental factors constant except for the fertilizer.
Where should the independent and dependent variables of Levi's experiment be placed when graphed?
Select all that apply.
the amount of fertilizer;y-axis
plant height;x-axis
the amount of fertilizer;x-axis
plant height; y-axis
Answer:
the amount of fertilizer; x-axis
plant height; y-axis
Explanation:
The independent and dependent variables of Levi's experiment placed when graphed are the amount of fertilizer and the y-axis. Option B is correct.
What are independent and dependent variables?The independent variables are those which are not dependent on other factors for their working or cannot be influenced by any other factor and the dependent variable is just the opposite of this one.
The experiment depends on the height of the plant but the fertilizer is independent of to work of the plant and fertilizer is independent and high and depends on other factors.
Therefore, Option B is correct. independent and dependent variables of Levi's experiment placed when graphed are the amount of fertilizer and the y-axis.
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A star is estimated to have a mass of 2.0 x 10 ^36kg. Assuming it to be a sphere of average radius of 7.0 x 10 ^5 km. Calculate the average density of the star in g/cm^3 and in lb/ft^3
Answer:
a) 1.392 x 10^6 g/cm^3
b) 8.69 x 10^7 lb/ft^3
Explanation:
mass of the star m = 2.0 x 10^36 kg
radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m
The density of substance ρ = mass/volume
The volume of the star = volume of a sphere = [tex]\frac{4}{3}\pi r^{3}[/tex]
==> V = [tex]\frac{4}{3}*3.142*(7.0*10^8)^{3}[/tex] = 1.437 x 10^27 m^3
density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3
in g/cm^3 = (1.392 x 10^9)/1000 = 1.392 x 10^6 g/cm^3
in lb/ft^3 = (1.392 x 10^9)/16.018 = 8.69 x 10^7 lb/ft^3
A chemical equation is balanced when Group of answer choices the number of atoms of each element is the same in reactants and products. the charge on each atom is the same in reactants and products. the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products. the total number of ions is the same in reactants and products. the total number of molecules is the same in reactants and products.
Answer:
a
Explanation:
A chemical equation is said to balanced only when the number of atoms of each element is the same in both reactants and products side. Rest all options are absurd. Hence, option a is correct.
Balancing of the reaction has no relation with coefficient, molecules or charge of the elements
If the molarity of sugar is 1.1, what will the freezing point be?
Answer:
The freezing point will be -2.046°C.
Explanation:
The freezing point depression equation is [tex]\Delta T_f = k_f \cdot m \cdot i[/tex]
Where;
[tex]\Delta T_f[/tex] = The temperature depression of the freezing point
[tex]k_f[/tex]= The constant of freezing point depression which is solvent dependent = 1.86°C/m
i = The number of particles the substance decomposes into in solution = 1 for sugar (a covalent compound)
m = The molality of the solution = 1.1
Therefore, we have;
[tex]\Delta T_f = 1.86 \times 1.1 \times 1 = 2.046 ^{\circ}C[/tex]
Therefore the freezing point will be 0 - 2.046°C = -2.046°C.
If a gas displays a solubility of 0.00290M at a partial pressure of 125 kPa, what is the proportionality constant for this gas in this solvent and at this temperature?
Answer:
The proportionality constant ( Henry’s constant) = 2.32 * 10^-5 M/kPa
Explanation:
Here in this question, we are concerned with calculating the proportionality constant for this gas.
Mathematically, we can get this from Henry law
From Henry law;
Concentration = Henry constant * partial pressure
Thus Henry constant = concentration/partial pressure
Henry constant = 0.00290 M/125 kPa = 2.32 * 10^-5 M/kPa
Which bond type is found in ammonium chloride. Select one: a. metallic b. covalent c. ionic
Answer:
ionic
Explanation:
In NH4Cl molecule, ionic bond is formed between NH4+ and Cl– ions, 3 covalent bonds are formed between N and three H atoms and one coordinate bond is formed between N and 1 H atom.
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Answer:
[tex]\boxed{\sf c. \ ionic}[/tex]
Explanation:
NH₄Cl is formed by an ionic bond between NH₄⁺ and Cl⁻ ions.
NH₄Cl (solid) ⇒ NH4⁺ (aqueous) + Cl⁻ (aqueous)
explain using diagrams how potassium forms the compound potassium flouride when it reacts with flourine
Answer:
The answer to your question is given below.
Explanation:
Potassium (K) has 19 electrons with electronic configuration of 2, 8, 8, 1.
Fluorine (F) has 9 electrons with electronic configuration of 2, 7.
Fluorine needs 1 electron to complete it's octet configuration.
Hence, potassium (K), will lose 1 electron to fluorine (F) to form potassium ion (K+) with electronic configuration of 2, 8, 8. The fluorine atom (F) will receive the 1 electron from potassium to form the fluoride ion (F-) with electronic configuration of 2, 8.
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pls balance the following chemical equation asap; Ca(OH)2 +CO2 = CaCO3+ H2O pls make it step by step
Answer:
Explanation:
Start by writing water as HOH
Ca(OH)2 +CO2 = CaCO3+ HOH
Next pay attention to the CO2 going to CO3
We need an oxygen.
Fortunately that is provided by the (OH)2
Now we have
Ca(OH)2 + CO2 ==> CaCO3 + HOH
and believe it or not, that is balanced as it is
The left side has 1 Ca. So does the right side
The Left side has 1 C. So does the right side.
The left side has 2 H. So does the right side
The left side has 2 oxygens (in Ca(OH2)) + 2 oxygens in CO2
So the equation is balanced.
Was is meant by the term suprenatural? Does science deal with the supernatural?
A. The term supernatural literally means (within nature) Science deals with the supernatural because it works within nature, not above it
B. The term supernatural literally means (above nature) Science does not deal with the supernatural because it works within nature, not above it
C. The term supernatural literally means (within nature) Science does not deal with the supernatural because it works above nature, not within it
D. The term supernatural literally means (above nature) Science deals with the supernatural because it also works with nature, not within it
Answer:
it's option D
Explain the different between a molecule and a compound.
Answer:
-A molecule is the smallesr part is compound whereas a compound is the combination of two or more atoms in a fixed proportion by wiehgt.
- A glass of water is an example of compound but a small portion of water can be called molecule.
The number of atoms in 2.0 moles of NaOH is _____ of 1.0 mole of H2O.
twice that
less than
more than
the same as
Answer:
The answer is the same as .
Explanation:
There are 3 atoms in NaOH, 1 sodium, 1 oxygen and 1 hydrogen.
There are 3 atoms in H2O, 2 hydrogen and 1 oxygen.
You work in the special effects department of a movie studio. You are
currently working on a superhero movie where the hero is very strong
and can punch through metal. For the next scene you need to replace a
6 inch by 6 inch square of a metal wall with a different material that will
crumble when the actor hits it. What could you use?
A. You could use Carbon(C)
B. You could use Potassium (k)
C. You could use Titanium (T)
D. You could use Manganese (Mn)
Answer:
The correct option is;
D. Manganese (Mn)
Explanation:
Manganese is very brittle, hard, iron like silvery-gray metal, that is difficult to melt. In air, Manganese slowly disintegrate in a similar manner to iron rusting in water
Manganese and iron have similar chemical and physical properties however manganese is more harder and more brittle than iron
A brittle material is one that easily breaks without deforming elastically
Therefore, manganese, due to its very iron like appearance and brittle nature will be suitable to replace the metal wall and crumble easily when the actor hits it.
H2SO4 is also called
a. king of acid
b. king of chemical
c. blue vitriol
d. Antacid
Answer:
[tex]\huge\boxed{King\ of \ Acid}[/tex]
Explanation:
H2SO4 (also called sulfuric acid) is also called King of Acids. It is a highly reactive acid.
Answer:
[tex]\large \boxed{\mathrm{a. \ king \ of \ acid }}[/tex]
Explanation:
[tex]\sf H_2SO_4[/tex] or sulfuric acid is known as the king of acid. It is a very reactive acid and is a strong acid in general.
3.87 moles of iron bromide yielded10.4 moles of sodium bromide
Answer: 89.57 %
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Please help me...
Atoms of elements X, Y and Z have 16, 17 and 19 electrons, respectively. Atoms of argon have 18 electrons.
a Determine the formulae of the compounds formed by the combination of the atoms of the elements:
(i) X and Z
(ii) Y and Z
(iii) X with itself.
b In each of the cases shown in
A (i)–(iii) above, name the type of chemical bond formed.
c Give two properties you would expect to be shown by the compounds formed in an (ii) and an (iii).
Answer:
a 1) XZ2
2) YZ
3) X2
b 1) Ionic bond
2) Ionic bond
3) covalent bond
c) ionic compounds has high melting and boiling point
ionic compounds can conduct electicity in aqueous form
covalent compounds have electrons shared between the atoms
covalent compounds have lower melting point compared to ionic compound
Answer:
(i) XZ = Potassium Sulfide [K2SO4]
(ii) YZ = Potassium Chloride [KCI]
(iii) X = Sulfur [S]
b) (i) Ionic Bond. (ii) Ionic Bond. (iii) Covalent Bond.
c) (i) Ionic compounds have high melting and boiling points.
(ii) Ionic compounds can conduct electricity in a molten state or a solution as they have ions that can move and carry charge.
(iii) Covalent compounds have low melting and boiling points.
(iv) Covalent compounds can not conduct electricity as all electrons are involved in bonding so there are no free electrons or ions to carry the charge.
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calculate the pH of 500cm3 of 0.2mol/dm3 Ca(OH2), assume complete ionisation
Answer:
The pH of 500 cm³, 0.2 mol/dm³, Ca(OH₂) is ≈ 13.6
Explanation:
The given parameters are;
Concentration of the calcium hydroxide, Ca(OH₂) = 0.2 mol/dm³
Volume of the calcium hydroxide, Ca(OH₂) = 500 cm³
Given that the calcium hydroxide, Ca(OH₂), undergoes complete ionization in water, complete dissociation, we have;
Ca(OH₂) ⇄ Ca²⁺ + 2 OH⁻
Therefore, we have;
2 moles of [OH⁻] for each mole of Ca(OH₂) which gives the concentration of [OH⁻] as
[OH⁻] = 2 × 0.2 ≈ 0.4 mol/dm³
The pH is given by the formula
pH = 14 + ㏒₁₀ [OH⁻]
pH = 14 + ㏒₁₀ (0.4) = 14 - 0.3979 = 13.6021 ≈ 13.6
The pH of the 500 cm³ 0.2 mol/dm³ Ca(OH₂) ≈ 13.6.
what is mean by stakeholder
Answer:
a stakeholder is a party that has an interest in a company and can either effect or be affected by the business. the primary stakeholder in a typical corporation are its investors , employees, customers and supplies.write the formula of three compounds which you know and name the elements in them
Answer:
[tex]\boxed{\sf{view \ explanation}}[/tex]
Explanation:
Compound definition:
A compound is a chemical substance formed by two or more chemically bonded elements.
Three compounds:
Water is a compound with the formula [tex]\sf H_2O[/tex].
Two hydrogen atoms and one oxygen atom is present in one molecule of water.
Sodium chloride or table salt is a compound with the formula [tex]\sf NaCl[/tex].
One sodium atom and one chlorine atom is present in one molecule of sodium chloride.
Ammonia is a compound with the formula [tex]\sf NH_3[/tex].
In one molecule of ammonia, one nitrogen atom and three hydrogen atoms are present.
Answer:
See below
Explanation:
Three compounds are:
1) [tex]\mathrm {H_{2}SO{4}}[/tex] [Sulfuric acid]
The elements in this compound are hydrogen (H) , Sulfur (S) and Oxygen (O).
2) [tex]\mathrm {NaOH}[/tex] [Sodium hydroxide]
The elements in this compound are Sodium (Na) , Oxygen (O) and Hydrogen (H).
3) [tex]\mathrm {HCl}[/tex] [Hydrochloric acid]
The elements are Hydrogen (H) and Chlorine (Cl).
Which of these is true about electrons? posses a positive electrical charge of one (+1) have a negative electrical charge of one (-1) indicates the number of protons in each atom equals the sum of protons plus neutrons in each atom
Answer:
have a negative electrical charge of one (-1)
Explanatio
Electrons have an electrical charge of negative one. When you think electron, always think -1
how to unscramble dtneinreigs
Answer:
Ingredients OR tenderising
Explanation:
please help :) How can scientists ensure that their data are reliable? A) by making a single observation B) by recording values without units C) by keeping the results private D) by repeating trials during an experiment
Answer:
D. by repeating trials during an experiment
Explanation:
chile its actually d
Explanation:
