Classify each of the observed changes according to whether or not they are likely to represent evidence that a chemical reaction is occurring when performing an experiment.
May be evidence of a chemical reaction Not evidence of a chemical reaction
a solution color becoming less intense
due to dilution
bubbles (sas formation) changes in color
precipitation
explosion or fire
Answer Bank
a solid liquifying change in temperature solution colors mixing
Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Magnesium and Copper Sulfate react to form Magnesium Sulfate and Copper in the following equation.
Mg + CuSO4 -> MgSO4 + Cu
Answer:
B: Single Displacement Reaction
Explanation:
A single replacement reaction, sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.
A + BX -> B + AX
For example:
Cation Replacement
Zn + CuCl2 -> ZnCl2 + Cu
Anion Replacement
Br2 + 2Ki -> 2KBr + I2
You just switch either the cation with another anion or switch an anion with another cation.
Hope it helped!
The following chemical reaction takes place in aqueous solution:
AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)
Write the net ionic equation for this reaction.
The net ionic equation : Ag⁺(aq)+l⁻(aq) ⇒ Agl(s)
Further explanationGiven
Reaction
AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)
Required
The net ionic equation
Solution
The equation of a chemical reaction can be expressed in the equation of the ions
In the ion equation, there is a spectator ion that is the ion that does not react because it is present before and after the reaction
When these ions are removed, the ionic equation is called the net ionic equation
AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)
Ag⁺(aq)+F⁻(aq)+Na⁺(aq)+l⁻(aq) ⇒ Agl(s)+Na⁺(aq) + F⁻(aq)
Ag⁺(aq)+l⁻(aq) ⇒ Agl(s)
C3H8 + 5 O2 → 3 CO2 + 4 H2O
How many grams of oxygen does it take to produce 90.6 grams of Carbon Dioxide
Answer:
Mass = 112 g
Explanation:
Given data:
Mass of CO₂ produced = 90.6 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂+ 4H₂O
Number of moles of CO₂:
Number of moles = 90.6 g/ 44 g/mol
Number of moles = 2.1 mol
Now we will compare the moles of CO₂ and oxygen:
CO₂ : O₂
3 : 5
2.1 : 5/3×2.1 = 3.5
Mass of oxygen needed:
Mass = number of moles × molar mass
Mass = 3.5 mol × 32 g/mol
Mass = 112 g
According to the following reaction, how many moles of phosphorus trichloride will be formed upon the complete reaction of 25.4 grams of phosphorus (P_4) with excess chlorine gas?
phosphorus (P_4) (s) - chlorine (g) --> phosphorus trichloride (l)
.....moles phosphorus trichloride
Answer:
0.82 mole of PCl₃
Explanation:
We'll begin by calculating the number of mole in 25.4 g of P₄. This can be obtained as follow:
Mass of P₄ = 25.4 g
Molar mass of P₄ = 4 × 31 = 124 g/mol
Mole of P₄ =?
Mole = mass / Molar mass
Mole of P₄ = 25.4 / 124
Mole of P₄ = 0.205 mole
Next, the balanced equation for the reaction. This is illustrated below:
P₄ + 6Cl₂ —> 4PCl₃
From the balanced equation above,
1 mole of P₄ reacted to produce 4 moles of PCl₃
Finally, we shall determine the number of mole of phosphorus trichloride, PCl₃, produced by the reaction of 25.4 g (i.e 0.205 mole) of P₄. This can be obtained as follow:
From the balanced equation above,
1 mole of P₄ reacted to produce 4 moles of PCl₃.
Therefore, 0.205 mole of P₄ will react to produce = 0.205 × 4 = 0.82 mole of PCl₃
Thus, 0.82 mole of PCl₃ was obtained from the reaction.
Sns
Station 5
Find the formula for the following
compounds:
Chromium (II) Oxide
Chromium (III) Oxide
Lead (II) Phosphide
Mercury (0) Sulfide
Manganese (11) Nitride
Is sodium hydroxide an alkali or an insoluble base
Trey was asked to build a working model of a landform for a science project. He chose to build a model of a volcano.
Trey formed a base out of clay and then painted the model so it resembled a cinder cone volcano.
Finally, Trey mixed baking soda, vinegar, and red food coloring in the base, so it mimicked lava flowing out of the volcano. Once
he was finished with his project, Trey's teacher asked how useful his model was.
What factor best determines the usefulness of the model?
A. how closely the model's color matches the real world
how closely the model's behavior matches the real world
C. how closely the model's size matches the real world
how closely the model's composition matches the real world
B.
D.
Answer:
The answer is "how closely the model's behavior matches the real world "
Explanation:
Your options were glitched out, so it only showed A and C, and B and D were blank so lol
What is the relationship between the mass of the boat and the mass of the displaced
liquid?
The mass of the boat is equal to the mass of the liquid which is displaced by placing the boat in the liquid.
What is Archimedes' Principle?
Archimedes' Principle states that the buoyant force of the object is equal to the weight of the water which is displaced by the boat. If the weight of the water that is displaced by the boat is less than that of the weight of the boat, then in this case the boat sinks. Archimedes' principle or the buoyant force is very useful for the calculation of the volume of an object that does not have a regular shape.
The mass of the displaced liquid is always equal to the volume of the liquid multiplied by the density of the fluid. When a boat is placed in the water, the volume of displaced water is equal to the mass of the boat which is placed in it.
Learn more about Displacement here:
https://brainly.com/question/11934397
#SPJ2
how do you think you can use lenses and mirrors to change the direction and intensity of a light wave?
what element has greatest atomic radius from group 3?
Answer:
i think iron
Explanation:
i not sure with my ans
Pressure is often defined as
Answer:
Pressure is often defined as a measure of force applied on an area, or over a unit area.
Explanation:
An idea based on observations with no experimental evidence is a:
any two substances which are odourless
Answer:
This question perplexes me somewhat. If we as humans are not able to detect a scent or odor from certain substances, that does not of necessity mean those substances are not giving off an odor, and are therefore not “truly” odorless, just odorless to the less sensitive noses of humans.
Water is supposedly odorless, but I know quite well of a test where subjects did a blind tasting, only instead of wine these people were tasting Australian waters, sourced from different locations around the country.
All of these tasters (professionals) were able to differentiate the waters and from what I recall, were all accurate. These wine buffs use their palates as well as their taste-buds, so, were there no odor, their task would have had a greater degree of difficulty.
My own baby sister has such a sensitive palate that she can tell you if you serve her a glass of water from the fridge whether that water was fresh, straight from the tap (unfiltered), filtered or had been boiled before and whether it had been boiled for more than five minutes or not. Truly.
So I would find it difficult to answer your question, “What substances are truly odorless?” , because I am not sure of the criteria you mean by “truly” odorless. In other words, If you are talking about zero degrees, are you talking of the freezing point of water, absolute zero or zero degrees Kelvin?
I’m sure there are substances that are odorless, to humans, but are those same substances “truly” odorless, or only to our perception of them?
Hope this helps, have a wonderful day/night, and stay safe!
WILL GIVE BRAINLIEST
Answer:
1. True
2. resting position
3. 5 cm
4. Compressions
5. false
6. 7 m
7. true
8. second one has more amplitude
9. True
10. true
Explanation:
How fast do electromagnetic waves travel? *
A the speed of sound
It depends on how fast the magnet in the generator that produces them is moving
At the speed of light
It depends on how many amps you pass through the coiled wire in the generator that
produces them.
what does the ideal gas law describe
Answer: the law that the product of the pressure and the volume of one gram molecule of an ideal gas is equal to the product of the absolute temperature of the gas and the universal gas constant.An ideal gas is a gas that conforms, in physical behaviour, to a particular, idealized relation between pressure, volume, and temperature called the ideal gas law
What is true about atomic radius trends on the periodic table?
A. Atomic radius decreases along periods and decreases down groups.
B. Atomic radius decreases along periods and increases down groups.
C. Atomic radius increases along periods and decreases down groups.
D. Atomic radius increases along periods and increases down groups.
It is not b
Answer:
D
Explanation:
Just took the test, Hope this helps!
Answer:
B. Atomic radius decreases along periods and increases down groups.
Explanation:
It decreases in period because of addition of proton effective nuclear charge increase and atomic radius decreases.
Atomic radius increases in group because of addition of shells
A(n)_________contains only one type of atom, whereas a(n)_________ is composed of two or more different elements bonded together. A(n)___________ also contains more than one substance, but these can be separated by physical means, whereas the components of a compound cannot.
Answer:
1. Element
2. Compound
3. Mixture
Explanation:
Elements and compounds are both pure substances. ELEMENTS are substances that contain only one type of atom. For example, Cl2 contains only chlorine atoms. COMPOUNDS, on the other hand, contain atoms of two or more elements that are chemically joined together. For example, CaCl2 contains atoms of calcium and chlorine.
MIXTURES are another kind of substances that contains more than one substances, however, unlike compounds, they are not chemically joined. Mixtures can easily be separated by physical means.
A compound is found to contain 7.962 % silicon , 20.10 % chlorine , and 71.94 % iodine by mass.
a. The empirical formula for this compound is_______ .
b. The molar mass for this compound is 352.8 g/mol. The molecular formula for this compound is:_____
Answer:
A. Empirical formula => SiCl₂I₂
B. Molecular formula = SiCl₂I₂
Explanation:
From the question given above, the following data were:
Silicone (Si) = 7.962 %
Chlorine (Cl) = 20.10 %
Iodine (I) = 71.94 %
Molar mass of compound = 352.8 g/mol
Empirical formula =?
Molecular formula =?
A. Determination of the empirical formula of the compound.
Si = 7.962 %
Cl = 20.10 %
I = 71.94 %
Divide by their molar mass
Si = 7.962 / 28 = 0.284
Cl = 20.10 / 35.5 = 0.566
I = 71.94 / 127 = 0.566
Divide by the smallest
Si = 0.284 / 0.284 = 1
Cl = 0.566 / 0.284 = 2
I = 0.566 / 0.284 = 2
Empirical formula => SiCl₂I₂
B. Determination of the molecular formula of the compound.
Empirical formula => SiCl₂I₂
Molar mass of compound = 352.8 g/mol
Molecular formula =?
Molecular formula = [SiCl₂I₂]ₙ
[SiCl₂I₂]ₙ = 352.8
[28 + (2×35.5) + (2×127)]n = 352.8
[28 + 71 + 254]n = 352.8
353n = 352.8
Divide both side by 353
n = 352.8 / 353
n = 1
Molecular formula = [SiCl₂I₂]ₙ
Molecular formula = [SiCl₂I₂]₁
Molecular formula = SiCl₂I₂
HELPPPPPPPPPPPPPPPPPP
Answer:
*helps and doesnt get deleted*
Explanation:
What is made when a salt is dissolved in water?
A) a precipitate
B) a compound
C) a solution
D) a mixture
Answer:
D.Mixture
Explanation:
When Salt dissolves in water a homogeneous mixture is formed, because the different components are mixed evenly within the substance.
What is molality mean
Answer:
Molality (m), or molal concentration, is the amount of a substance dissolved in a certain mass of solvent. It is defined as the moles of a solute per kilograms of a solvent.
Explanation:
Look in Dictionary
All the iron in a 2.000 g tablet was dissolved in an acidic solution and converted to Fe2+. This was then titrated with KMnO4. The titration required 27.50 cm3 of 0.100 mol dm-3 KMnO4. Calculate the total mass of iron in the tablet and its percentage by mass.
Answer:
0.768g of Fe are in the tablet = 38.4% by mass of Fe in the tablet
Explanation:
The balanced redox equation of Fe²⁺ with KMnO₄ in acidic medium is:
5Fe²⁺ + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O
Where 5 moles of Fe²⁺ react per mole of KMnO₄
The moles required of KMnO₄ are:
27.50cm³ * (1dm³ / 1000cm³) = 0.0275dm³ * (0.100mol / dm³) = 0.00275mol KMnO₄
Moles of Fe²⁺ are:
0.00275mol KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.01375moles of Fe²⁺
In grams (Molar mass Fe: 55.845g/mol):
0.01375moles of Fe²⁺ * (55.845g/mol) =
0.768g of Fe are in the tabletAnd percentage is:
0.768g Fe / 2.000g * 100 =
38.4% by mass of Fe in the tabletWhich of the following does NOT determine local weather patterns?
Answer:
do you have a picture of the choices?
Is mass based on gravity. True or false
Answer:
true mass is based on gravity
Answer:
true
Explanation:
mass based on gravity
How many moles are in 25.58 grams of H20?
Explanation:
1.42 Moles are there
What is the frequency of a photon that has a wavelength of 6.58 x 10-8m?
Answer:
6 x 10 (power to the 15) H2
Answer:
i dont know the answer but you could search up photon calculator, hope this helps (im very sorry i couldnt help but i havent learned about that yet, im in 9th grade)
How can scientific themes apply to many branches of science?
A. All types of scientists have agreed on them.
B. The different branches of science are connected.
C. Different themes exist for the different branches.
O D. The themes are all based on the same basic units.
Answer:
b) different branches of science are connected
Answer:
b
Explanation:
a p e x :)
A sodium bromide solution is added to a beaker containing aqueous chlorine. What would happen?
A) Write the complete chemical equation
B) Write the dissociated ionic equation
C) Write the net ionic equation
D) List any spectator ions
Answer:
See detailed explanation.
Explanation:
Hello!
In this case, for the described chemical reaction, we can proceed as follows:
A) For the complete chemical reaction we note down every reacted and produced species as well as the proper balancing process:
[tex]2NaBr(aq)+Cl_2(aq)\rightarrow 2NaCl(aq)+Br_2(g)[/tex]
In which gaseous bromine may give off.
B) The dissociated ionic equation requires the ionization of the aqueous species in ions, expect for chlorine which is not ionized:
[tex]2Na^+(aq)+2Br^-(aq)+Cl_2(aq)\rightarrow 2Na^+(aq)+2Cl^-(aq)+Br_2(g)[/tex]
C) For the net ionic equation we cancel out the sodium ions as they are at both reactants and products:
[tex]2Br^-(aq)+Cl_2(aq)\rightarrow +2Cl^-(aq)+Br_2(g)[/tex]
D) Based on C) we infer that the spectator ions here are the sodium ions.
Best regards!