Answer:
it's the third one
Explanation:
in the first one oxygen molecules aren't balanced
the second ok me oxygen isnt balanced
and the fourth one hydrogen isn't balanced
hope it helps ;)
A balanced equation is a representation in which the coefficients of the individual atoms of a molecule or compound are the same on both the left and right of the equation.
The correct answer is:
Option C. Zn + 2 HCl --------> ZnCl₂ + H₂
This can be explained as:
In the first equation, the number of H and O atoms are not balanced.In the second case, the atoms of hydrogen and oxygen are not the same on the sides of the equation.In the third reaction between zinc and hydrochloric acid, all the atoms of the reaction are balanced.In the fourth reaction, the hydrogen atoms are not balanced.Therefore zinc and hydrochloric acid reaction are balanced.
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Can someone please help me answer these Questions pleaseee
How many grams are in 9.30 x 10-2 moles of calcium phosphate, Caz(PO3)2?
a. 25.9 g b. 17.65 g
c. 0.064 g
d. 259 g
Answer:
25.9 g
Explanation:
Given that,
No of moles of calcium phosphate, [tex]n=9.3\times 10^{-2}[/tex]
We need to find how many grams of calcium phosphate has this much of no of moles.
Mass divided by molar mass is equal to the no of moles on a molecule.
The molar mass of calcium phosphate is 310.18 g/mol
Using the concept of no of moles as follows :
[tex]n=\dfrac{m}{M}\\\\m=n\times M\\\\m=9.3\times 10^{-2}\times 310.18\\\\m=28.84\ g[/tex]
Out of given options, option (a) i.e. 25.9 g is the correct answer.
Oxidation is the process by which _______.
A. an atom gains electrons
B. an atom loses electrons
C. negative ions are attracted to the anode
D. positive ions are attracted to the anode.
E. positive ions are attracted to the cathode.
Free Brainly !! What is the cation and its' charge for the following compound?
CaCl2
Answer:
calcium cation
Formula and structure: The chemical formula of calcium chloride is CaCl2, and its molar mass is 110.983 g/mol. It is an ionic compound consisting of the calcium cation (Ca2+) and two chlorine anions (Cl-).
Explanation:
why copper is important in electrical works?
For what is the Endocrine system responsible for?
I will report your answer If its just to get points
A: Breathing.
B: Maintaining Homostasis.
C: Ridding of waste.
D: Protecting from Invaders.
Answer:
B: Maintaining Homostasis
Explanation:
Calculate the mass of one mole of these substances.
a. NH4Cl
b. NH4NO3
c. AlCl3
Helppp plss :)
Answer:
a. 53.5 g/mol
b. 80.06 g/mol
c. 133.33 g/mol
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableMolar Mass - 1 mol per x grams substanceExplanation:
Step 1: Define
a. NH₄Cl
b. NH₄NO₃
c. AlCl₃
Step 2: Find masses
Molar Mass of N - 14.01 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Al - 26.98 g/mol
Molar Mass of Cl - 35.45 g/mol
Step 3: Calculate compound masses
Molar Mass of NH₄Cl - 14.01 g/mol + 4(1.01 g/mol) + 35.45 g/mol = 53.5 g/mol
Molar Mass of NH₄NO₃ - 2(14.01 g/mol) + 4(1.01 g/mol) + 3(16.00 g/mol) = 80.06 g/mol
Molar Mass of AlCl₃ - 26.98 g/mol + 3(35.45 g/mol) = 133.33 g/mol
How many moles of MgCO3 are in 2.57g of MgCO3?
Answer:
0.0305 moles of MgCO₃
Explanation:
In order to solve this problem, we first need to calculate the molecular weight of MgCO₃:
MgCO₃ MW = Atomic mass Mg + Atomic mass C + (Atomic mass O)*3MgCO₃ MW = 24.3 + 12 + 16*3 = 84.3 g/molFinally we divide the mass by the molecular weight, to calculate the number of moles:
2.57 g MgCO₃ ÷ 84.3 g/mol = 0.0305 moles.Julie finds a snail on the sidewalk and wants to know whether or not the snail moves throughout the day. She places a single mark on the sidewalk next to the snail.
What will Julie use the mark for initially?
determining how fast the snail moves
acting as a standard unit of measure
determining the displacement of the snail
acting as a reference point for detecting motion
Answer:
b-acting as a standard unit of measure
Explanation:
Julie uses the mark for initially acting as a standard unit of measure. The correct option is b.
What is observation?Recognizing and writing down an occurrence or fact is the process of observation, which frequently entails measuring it with tools. Utilizing tools for measurement is frequently required when recognizing and documenting an occurrence or fact. Written observations taken during or right after fieldwork are referred to as field notes.
They are essential for comprehending occurrences observed in the field. Scratch notes, diaries, and notebooks are common formats for field notes. The process of observation is essential in science. Snails are the molluscan. It comes under zoological study.
Therefore, the correct option is b. acting as a standard unit of measure
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Drag the tiles to the correct boxes to complete the pairs.
Chromium is a transition metal, and oxygen has an oxidation number of -2. Use this information to match each compound to its chemical formula.
Which two changes of state can be caused by removing thermal energy from a substance? choose two
A. Vaporization
B. Condensation
C. Deposition
D. Sublimation
Answer:
B and C
Explanation:
The correct answer is Condensation and Deposition
Answer:
Explanation:
It is Deposition and Condensation
What similarity is there between a straight-chain four-carbon alkane and alkyne?
A) the boiling points
B) the number of single bond s
C) the number of hydrogen atoms
D) the way the atom's rotate within the molecules
potential
1
Fill in the blanks to complete the sentences.
food
Energy is the ability to do
work
which is what makes
matter
move or change.
physical
kinetic
Objects at rest have stored
energy, while objects in motion
have
energy
In order to exercise and do other
activities, our bodies need
the chemical energy stored in
HELPPPPP
Answer:
work
matter
potentioal
kinetic
physical
food
Explanation:it is in the order above ^
1 poin
9. In an experiment, the one variable that is changed on purpose by the
scientist is called the
controlled variable
experimental variable
independent variable
dependent variable
Answer:
It's called Independent variable
Explanation:
....
Question 1 of 10
What would you need to do to calculate the molality of 10 mol of NaCl in 200
mol of water?
A. Convert the 200 mol of water to kilograms of water.
B. Convert the 200 mol of water to liters of water.
C. Convert the 10 mol of NaCl to grams of NaCl.
O D. Convert the 10 mol of NaCl to kilograms of NaCl.
SUBMIT
A. Convert the 200 mol of water to kilograms of water.
Further explanationMolality (m) shows the number of moles dissolved in every 1000 grams(1 kg) of solvent.
[tex]\tt m=n\times \dfrac{1000}{p}[/tex]
m = Molality
n = number of moles of solute
p = Solvent mass (gram)
or
[tex]\tt m=\dfrac{mol~solute}{kg~solvent}[/tex]
solute = 10 mol NaCl
solvent = 200 mol water⇒Convert to kilograms of water.
Para un sistema, el valor de la constante que resulta del cociente entre el producto de la presión y el volumen con la temperatura es de 0,03 (atmxL/K). ¿cuál debe ser el valor de la temperatura del sistema para el volumen y la presión tengan valores 4500mL y 4,5atm?
Answer:
675 K
Explanation:
[tex]\dfrac{P_1V_1}{T_1}=0.03\ \text{atm L/K}[/tex]
Presión del sistema 2 = [tex]P_2=4.5\ \text{atm}[/tex]
Volumen del sistema 2 = [tex]V_2=4500\ \text{mL}=4.5\ \text{L}[/tex]
De la ley de los gases ideales tenemos la relación
[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow 0.03=\dfrac{4.5\times 4.5}{T_2}\\\Rightarrow T_2=\dfrac{4.5\times 4.5}{0.03}\\\Rightarrow T_2=675\ \text{K}[/tex]
La temperatura del sistema para el segundo sistema es 675 K.
What does aqueous mean in a chemical equation?
Answer: a solution where the solvent is water
Explanation: solute ions which are known as the dissolvable ions and molecules are surrounded by water molecules and then get incorporated into the bonding network of water
Calculate the pH of 0.02 M methanoic acid where Ka = 1.6 x 10^-4 M.
Answer:
pH = 2.75
Explanation:
Methanoic acid, HCOOH, is in acidic equilibrium:
HCOOH ⇄ HCOO⁻ + H⁺
And Ka is defined as:
Ka = 1.6x10⁻⁴ = [HCOO⁻] [H⁺] / [HCOOH]
As both HCOO⁻ and H⁺ ions comes from the same equilibrium, we can solve these concentrations assuming the HCOOH produce X of both HCOO⁻ and H⁺ ions:
1.6x10⁻⁴ = [HCOO⁻] [H⁺] / [HCOOH]
1.6x10⁻⁴ = [X] [X] / [0.02M]
3.2x10⁻⁶ = X²
X = 1.79x10⁻³M = [H⁺]
As pH = -log [H⁺]
pH = 2.75The pH of the 0.02 M methanoic acid is 2.75 acid when the dissociation constant is [tex]1.6 \times 10^{-4} \rm \ M.[/tex]
At equilibrium, the dissociation of Methanoic acid,
HCOOH ⇄ HCOO⁻ + H⁺
In the reaction, Methanoic acid dissociates to form HCOO⁻ and H⁺. So, the concentration of both products will be equal.
pH can be calculated by using Ka,
[tex]\bold{Ka = \dfrac {[HCOO^-] [H^+] }{[HCOOH]}}[/tex]
Where,
Ka - dissociation constant = 1.6x10⁻⁴
[HCOOH ] - concentration of Methanoic acid = 0.02 M
[tex]\bold{1.6 \times 10^{-4} M.= \dfrac {[HCOO^-] [H^+] }{[HCOOH]}}[/tex]
Let the concentration of each product is [tex]x[/tex]
So,
[tex]\bold{1.6 \times 10^{-4} \ M}= \dfrac {[x] [x] }{[0.02]}}\\x^2 = 3.2\times 10^{-6}\\x = 1.79\times 10^{-3}\rm \ M[/tex]
Put the value in the pH formula,
[tex]\bold {pH = - log [H^+]}\\\\\bold {pH =- log \ 1.79\times 10^{-3}\rm \ M}\\\\\bold {pH = 2.75 }[/tex]
Therefore, The pH of the 0.02 M methanoic acid is 2.75 acid when the dissociation constant is [tex]1.6 \times 10^{-4} \rm \ M.[/tex]
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Two spheres are measured and are both found to have a mass of 24 grams.If sphere A has a density of 12 g/mL and sphere B has a density of 3 g/mL.What can you conclude about the volume of each?
Answer:
Volume of sphere A = 2 mL
Volume of sphere B = 8 mL
The volume of sphere B is 4 times the volume of sphere A.
Explanation:
We'll begin by calculating the volume of each sphere.
Data obtained from the question include:
Sphere A:
Mass = 24 g
Density = 12 g/mL
Volume =?
Sphere B:
Mass = 24 g
Density = 3 g/mL
Volume =?
Next, we shall determine the volume of each sphere. This can be obtained as follow:
For sphere A:
Density = mass /volume
12 = 24/volume
Cross multiply
12 × volume = 24
Divide both side by 12
Volume = 24/12
Volume = 2 mL
For sphere B:
Density = mass /volume
3 = 24/volume
Cross multiply
3 × volume = 24
Divide both side by 3
Volume = 24/3
Volume = 8 mL
Summary:
Volume of sphere A = 2 mL
Volume of sphere B = 8 mL
Comparing the volume of both sphere, we have:
Va /Vb = 2/8
Va /Vb = 1/4
Cross multiply
Va × 4 = Vb
Vb = 4Va
From the above illustration,
The volume of sphere B is 4 times the volume of sphere A.
It has been concluded that the volume of sphere A has been 4 times greater than the volume of sphere B.
Density can be defined as the mass per unit volume. Density can be expressed as:
Density = [tex]\rm \dfrac{Mass}{Volume}[/tex]
Sphere A has a mass of 24 grams, and a density of 12 g/ml.
Sphere B has a mass of 24 grams and a density of 3 g/ml.
Since the spheres have the same mass, the relationship can be given as:
Density of A × Volume of A = Density of B × Volume of B
12 × Volume of A = 3 × Volume of B
4 × Volume of A = Volume of B
Thus, it has been concluded that the volume of sphere A has been 4 times greater than the volume of sphere B.
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Hello can someone help me out i will give brainliest. Its chemical or physical hw
Answer:
16- physical
14- chemical
15- chemical
13- physical
Explanation:
A chemical change would be something like the burning of wood, it's an object changing into something new, or something changing. A physical change would just basically altering something like bending wood, it's still wood whether or not you bend it.
Determine whether each statement is an example of a physical change or a chemical change. Paper is shredded. physical chemical
Answer:
That would be a physical change
Explanation:
A physical change is when you are changing the physical properties of something but not changing its overall identity and a chemical change is when yo are changing the physical properties and changing its identity .
Ex. Ripping a dollar bill- Physical change
Burning a dollar bill- chemical change
Answer:
first one is physical , second one is chemical
Explanation:
1
Complete and balance the following equations : Al + NaOH +___--->_____+____
Answer:
Al + 3NaOH = Al(OH)₃ +3Na
Explanation:
The reaction is given as:
Al + NaOH = Al(OH)₃ + Na
This reaction is called a single displacement reaction in which one specie displaces another from a solution.
To balance the equation:
aAl + bNaOH = cAl(OH)₃ + dNa
a, b, c and d are the coefficient that will balance the equation:
Conserving Al;
a = c
Conserving Na;
b = d
Conserving O;
b = 3c
Conserving H;
b = 3c
Let a = 1, c = 1, b = 3 and d = 3
Al + 3NaOH = Al(OH)₃ +3Na
Why is Bohr diagram better than orbital diagram ?
Answer:
hfjdjdjdjdjdjdjd
Explanation:
rjeiejejejeje
Consider the Mg2+, Cl-, K+, and Se2- ions.The four spheres below represent these four ions, scaled according to ionic size. A) Match each ion to its appropriate sphere. B) In terms of size, between which of the spheres would yo find the (i) Ca2+ and (ii) S2- ions?
Answer:
A is Mg^2+
B is K^+
C is Se^2-
D is Cl^-
Ca^2+ lies between Mg^2+ and K^+
S^2- lies between K^+ and Se^2-
Explanation:
I have attached an image of the four spheres.
Remember that, cations are smaller in size than the corresponding atom atom because the formation of a cation often involves the removal of an entire shell. Anions are larger in size than the corresponding atom because an electron is added thereby expanding the electron cloud and size of the anion.
From left to right let us designate the spheres as ABCD.
A is Mg^2+
B is K^+
C is Se^2-
D is Cl^-
Ca^2+ lies between Mg^2+ and K^+
S^2- lies between K^+ and Se^2-
The size of the spheres, going from smallest to largest, would be: [tex]Mg^2^+[/tex], [tex]K^+[/tex], [tex]Ca^2^+[/tex], [tex]Cl^-[/tex], [tex]S^2^-[/tex], [tex]Se^2^+[/tex].
We can arrive at this answer because:
To know the size of the spheres of an ion, we must know if they are a cation or an anion and the number of electrons in each valence layer that is gained or donated.Cations are the ions that donate electrons. They are represented by the + symbol and get smaller and smaller as they donate electrons.Therefore, we can state that the cations [tex]Mg^2^+[/tex], [tex]K^+[/tex], [tex]Ca^2^+[/tex] have the smallest spheres.On the other hand, anions, represented by the - symbol , have the largest spheres because they receive electrons.In this case, the [tex]Cl^-[/tex], [tex]S^2^-[/tex], [tex]Se^2^-[/tex] anions have the largest spheres.This is because when donating electrons, the cations get the largest number of protons. This makes the cation nucleus attract the electronic layers, decreasing their extension. In anion, the opposite happens and the increase of electrons increases the extension of the electronic layers.
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Identify the correctly written chemical reaction.
A. Reactant + Product → Reactant + Product
B. Product + Product → Reactant + Reactant
C. Reactant + Reactant = Product
O
D. Reactant + Reactant → Product + Product
Answer:
eek um A.The substance(s) to the left of the arrow in a chemical equation are called reactants. The substance(s) to the right of the arrow is called products.
Explanation:
4. The heat of
fusion of a
substance is
80 J/g. How
much energy
is required to
melt 25 g of
the
substance?
A. 2J
B. 25 J
C. 80 J
D. 2 kJ
It is 2 KJ
It is because the formula is :
q=m∆Hf
where m is the mass and ∆Hf is the heat fusion.
So, we get:
q=80×25
q=2000J or 2 KJ
What causes fireworks
Answer:
Explanation:
A
2.4 Propene reacts with steam to produce an alcohol, propanol.
Complete the equation for the reaction.
C3H6 + H2O
Answer:
C₃H₆ + H₂O = C₃H₈O
Explanation:
Hydration reactions (reactions involving converting an alkene to alcohol) have only one product, so there will be no byproduct along with propanol.
Propene reacts with steam to produce propan-2-ol. The reaction is C₃H₆ +H₂O[tex]\rightarrow[/tex]C₃H₈O. It is an example of hydration reaction.
What are hydration reactions?Hydration reaction is defined as a chemical reaction wherein a substance combines with water. In organic chemistry, when an unsaturated substance reacts with water it is called as hydration reactions.
The reaction involves breaking of hydroxyl bond in water which is highly exothermic releasing large amount of energy. Direct addition of water to an alkene is too slow and hence the rate is catalyzed by Lewis acids or Bronsted acids.
Hydration reactions are extensively used for industrial production of butanol and isopropanol,etc.The addition of water along the double bond in alkenes takes place according to Markovnikov's rule.
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Please help fast...please
Answer:
Radioactive
Explanation:
hope this helped! :)
Suppose the isotopic ratio of the two boron isotopes 10B (10.013 amu) and 11B (11.009 amu) in a sample has been altered from the ratio found in nature and now contains 33.36% 10B in the sample. Determine the atomic weight of this sample of this new boron element.
Answer:
The correct answer is 10.676 amu.
Explanation:
Based on the given information, the concentration of 10B left in the sample is 33.36%. Therefore, the percentage of 11B present will be,
11B = 100% - 33.36% = 66.64%
Now the atomic weight of the new boron element can be determined by adding the atomic masses of both the isotopes multiplied by its percentage.
Therefore,
= (10.013 amu * 33.36%) + (11.009 amu * 66.64%) / 100
= 10.676 amu