Answer:
CH (92.2% C; 7.8% H), or just CH2
help PLEASEEE !!!!!! will give brainliest !
Answer:
6. O₂ + Cu —> CuO
7. H₂ + Fe₂O₃ —> H₂O + Fe
8. O₂ + H₂ — > H₂O
9. H₂S + NaOH —> Na₂S + H₂O
10. Al + HCl —> H₂ + AlCl₃
Explanation:
6. Oxygen gas react with solid copper metal to form copper(II) oxide
Oxygen gas => O₂
Copper => Cu
copper(II) oxide => CuO
The equation is:
O₂ + Cu —> CuO
7. hydrogen gas and iron(III) oxide powder react to form liquid water and solid iron power
hydrogen gas => H₂
Iron(III) oxide => Fe₂O₃
Water => H₂O
Iron => Fe
The equation is:
H₂ + Fe₂O₃ —> H₂O + Fe
8. Oxygen gas react with hydrogen gas to form liquid water
Oxygen gas => O₂
hydrogen gas => H₂
Water => H₂O
The equation is:
O₂ + H₂ — > H₂O
9. Hydrogen sulphide gas is bubbled through a sodium hydroxide solution to produce sodium sulphide and liquid water
hydrogen sulphide => H₂S
sodium hydroxide => NaOH
Sodium sulphide => Na₂S
Water => H₂O
The equation is:
H₂S + NaOH —> Na₂S + H₂O
10. Hydrogen gas and aluminum chloride solutions are produced when solid aluminum react with hydrochloric acid
Aluminum => Al
Hydrochloric acid => HCl
hydrogen gas => H₂
Aluminum chloride => AlCl₃
The equation is:
Al + HCl —> H₂ + AlCl₃
humans have a total of 46 chromosomes therefore, humans inherit ____ chromosomes from each parent. (use numerals for the answer)
Answer:
23
Explanation:
there are 23 pairs of chromosomes
46 individula chromosomes
but each parnet contribute one chromosome to each pair
Answer:
23 :)
Explanation:
Potassium is an alkali metal that is one of the electrolytes needed by the human body to conduct nerve impulses. The majority of potassium
(93.26%) occurs as potassium-39. The rest is either potassium-40 (0.01%)
or potassium-41 (6.73%). *
pls show work for how you got answer!!
Answer:
39.13
Explanation:
To find that atomic mass of this potassium, we follow the steps below:
Given parameters:
Abundance of K - 39 = 93.26%
Mass of K - 39 = 39
Abundance of K - 41 = 6.73%
Mass of K - 41 = 41
To find the average atomic mass;
Average atomic mass =( mass x abundance of k -39 ) +( mass abundance of k- 41)
Average atomic mass = (39 x 93.26%) + (41 x6.73% ) = 39.13
Connect the group to the configuration.pleas help !!
Explanation:
The group number in the periodic table represents number of valence electrons of the elements in a certain group.
Group 1 : 2,8,1
Group 2 : 2,8,8,2
Group 3 : 2,8,3
Group 4: 2,4
Group 7 : 2,8,7
Answer:
2, 8 7 7 valence electrons Group 7
2, 8 , 1 1 valence electrons Group 1
2 8 3 3 valence electrons Group 3
2 4 4 valence electrons Group 4
2 8 8 2 2 valence electrons Group 2
Explanation:
The valency of an electronic configuration of an atom can be used to determine the group an element belongs.
The valency is the number of outermost shell electrons an atom contains.
So;
2, 8 7 7 valence electrons Group 7
2, 8 , 1 1 valence electrons Group 1
2 8 3 3 valence electrons Group 3
2 4 4 valence electrons Group 4
2 8 8 2 2 valence electrons Group 2
Which choice best describes a testable hypothesis?
A.) Carrots look better when given more water.
B.) Lilacs are better smelling than roses.
C.) Mountain lions travel over 100 km per day.
D.) The bacterium E. coli is worse than the bacterium S. aureus.
Answer:
A. carrots look better when given more water
The transfer of thermal energy from a warmer object to a cooler object is called
Answer:
heat transfer
what would cause the liquid in the thermometer to drop?
What causes surface water to move
Answer:
C - Wind
Explanation:
its C or wind because global wind systems control the surface water
Answer:
Wind
Explanation:
surface water from oceans move from the wind I assume it is the same for all bodies of water
What is an oxidation number?
a
The charge acquired by an atom in a chemical bond
b
The number of electrons involved in a chemical bond
c
The number of oxygen atoms an element will bond with
d
The number of oxygen atoms a compound has
Answer:
d
Explanation:
i hope it helps you good luck
There are two spheres of the same
size, one is metal and one is wood. Why
does the metal sphere have more mass?
Answer:
metal is heavier than wood.
Explanation:
metal is made of rock which doesn't have air in it while wood has air in it making it lighter
PLEASE HELP QUICK!
1.) SnO2 (s) + 2 H2 (g) → Sn (s) + 2 H2O (l)
What mass of water is produce when 79.0g of SnO2 are consumed in the reaction above?
2.) C3H8(g) + 5 O2 (g) → 3 CO2 (g)+ 4 H2O (g)
What volume of oxygen is required to completely combust 0.499L of propane (C3H8) at STP?
BRAINLIEST FOR GOOD ANSWERS TO BOTH.
Answer:
1) Mass = 18.864 g
2) V = 2.47 L
Explanation:
1) Given data:
Mass of water produced = ?
Mass of SnO₂ react = 79.0 g
Solution:
SnO₂ + 2H₂ → Sn + 2H₂O
Number of moles of SnO₂:
Number of moles = mass/molar mass
Number of moles = 79.0 g/ 150.71 g/mol
Number of moles = 0.524mol
Now we will compare the moles of SnO₂ and H₂O
SnO₂ : H₂O
1 : 2
0.524 : 2/1×0.524 =1.048 mol
Mass of water:
Mass = number of moles × molar mass
Mass = 1.048 mol × 18 g/mol
Mass = 18.864 g
2) Given data:
Volume of oxygen required = ?
Volume of C₃H₈ combust at STP = 0.499 L
Solution:
Chemical equation:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Number of moles of C₃H₈:
PV = nRT
R = general gas constant = 0.0821 atm.L /mol.K
1 atm × 0.499 L = n × 0.0821 atm.L /mol.K × 273.15 K
0.499 L atm.L = n × 22.43 atm.L /mol
n = 0.499 L atm.L / 22.43 atm.L /mol
n = 0.022 mol
Now we will compare the moles of propane and oxygen.
C₃H₈ : O₂
1 : 5
0.022 : 5/1×0.022 = 0.11 mol
Volume of oxygen required:
PV = nRT
R = general gas constant = 0.0821 atm.L /mol.K
1 atm × V = 0.11 mol × 0.0821 atm.L /mol.K × 273.15 K
1 atm × V = 2.47 atm.L
V = 2.47 atm.L / 1 atm
V = 2.47 L
What type of bond holds hydrogen (H) atoms together in a molecule of hydrogen?
A. Metallic
B. Polar Covalent
C. Nonpolar covalent
D. Hydrogen
Answer:
C. Nonpolar covalent
Explanation:
The type of bond that holds hydrogen(H) atoms together in a molecule of hydrogen is a non-polar covalent bond.
A covalent bond forms between two atoms with low or zero electronegativity difference. It is usually between non - metals or atoms of the same kind. When atoms of the same kind bonds as in hydrogen to form hydrogen gas, non-polar covalent bond is formed. This is because there is no charge separation.What is the molecular mass of a gas whose density is 1.25 grams per liter at STP?
STP = standard temperature and pressure
Use the formula:
d = MP/RT
where:
d = density = 1.25 g/L
M = molar mass (unknown)
P = pressure = 1 atm (standard pressure)
R = universal gas constant = 0.8206 L*atm/mol*K
T = temperature = 0C or 293.15 K (standard temperature)
1.25 g/L = M*(1 atm)/(0.08206 L*atm/mol*K)*(273.15 K)
M = 28.0 grams/mol
PLEASEEEE HELP MEE!
ASAP WILL GIVE BRAINLIEST TO CORRECT ANSWER!!!!⇔ AND WILL GIVE A SHOUTOUT
Answer:
2nd option
Explanation:
I WILL GIVE U BRAINLIEST IF UR CORRECT
Which of the following is always a result of a chemical reaction?
Hint: The questions says always.. only one best answer
A. Bubbles
B. Fire or smoke
C. Temperature change
D. A new substance
Answer:
D: a new substance
Explanation:
Chemical reaction
A change in matter that produces on or more new substances
Answer:
D. A new substance is always a result of a chemical reaction.
Explanation:
In a chemical reaction, one or more reactants reacts/decomposes to form one or more products.
Based on the contributions of early scientists, one can conclude that one discovery was
Answer:
the discovery of atomic structure.
Explanation:
Rutherford was a famous scientist who gave his theory of atomic structure.
Ernest Rutherford was a great physicist who is well known for his pioneering studies and discoveries about atoms and radioactivity. Rutherford was considered to be the greatest experimentalist after Michael Faraday.
Rutherford's atomic model was one of the greatest discoveries which provided many answers and solutions to the structure of atom and molecules that our earth is surrounded of.
Rutheford discovered that an atom has a tiny mass of positively charged particles in the centre of the atom called nucleus and negatively charged electrons surrounds the nucleus.
Bohr joined Rutherford in his studies and discovered many new facts about the structure of the atom based on the Rutherford's model. Today atomic model is the product of Rutherford atomic structure.
3. What range of numbers would you expect on the pH scale for an alkali? (1 mark)
Answer:
a pH above 7 is alkali
a pH lower than 7 is acidic
what is the soda's density if its volume is 384ML, and its mass is 402g?
Answer:
1.05 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question we have
[tex]density = \frac{402}{384} \\ = 1.046875[/tex]
We have the final answer as
1.05 g/mLHope this helps you
Please help fast
What statement is correct about wind turbines. A. They create Mechanical and electrical energy B. They transform wind energy to electrical energy C. Their total energy decreases when electricity is produced D. Their total energy increases when electricity is produced
Answer:
A.
Explanation:
sana makatulong follow mo ako please
A student uses a force of 46 Newtons to push her bike 57 meters. How much work has she done?
W = F x D
Answer:
The displacement is 0.05 meters. The angle between the upward force and the upward displacement is 0 degrees. The work for 1 push-up is approximately. W = 10 N * 0.05 m * cos 0 degrees = 0.5 Joules. If the squirrel does a total of 5.0 Joules of work, then it must have done about 10 push-ups.
Explanation:
what physical properties can be used to separate heterogeneous mixture's?
___ organisms only need one cycle of cell division to create offspring
Answer:
asexual organisms because they
self reproduce by fissure division instead of meiosis
65 grams of Potassium Chloride is dissolved to make 450 mL of solution. What is
the MOLARITY of this solution?
Some atoms are chemically stable and will not bond with atoms of other
elements. Describe atoms that are stable.
help
Answer:
The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.
Explanation:
Answer:
The stability of atoms depends on whether or not their outer-most shell is filled with electrons. If the outer shell is filled, the atom is stable. Atoms with unfilled outer shells are unstable, and will usually form chemical bonds with other atoms to achieve stability.
Explanation:
In which reaction is there a transformation of mass into energy? For A P E X
A. Two hydrogen atom fuse to form a helium atom
B. Ammonium nitrate breaks down into dinitrogen monoxide and water
C. Calcium oxide combines with water to form calcium hydroxide
D. Sodium combines with chlorine to form sodium chloride
What is the formula for an ionic compound that forms out of Sr and Br?
Group of answer choices
Sr and Br will not form an ionic compound.
Sr2Br
SrBr2
SrBr
Answer: St Br2
Explanation: Br has only one valence electrons and Sr has 2 valence electrons this is why we need 2 atoms of Br to for an ionic compound with 1 atom of Sr.
Additional Practice Questions
6. If you dissolve 2.31 g of barium hydroxide into 250 mL of water and the barium hydroxide is fully ionized, what will
your resulting pH be?
pH of solution = 13.033
Further explanationGiven
2.31 g Ba(OH)₂
250 ml water
Required
pH of solution
Solution
Barium hydroxide is fully ionized, means that Ba(OH)₂ is a strong base
So we use a strong base formula to find the pH
[OH ⁻] = b. Mb where
b = number of OH⁻ /base valence
Mb = strong base concentration
Molarity of Ba(OH)₂(MW=171.34 g/mol) :
[tex]\tt M=\dfrac{mol}{L}=\dfrac{2.31~g\div 171.34~g/mol}{0.25~L}\\\\M=0.054[/tex]
Ba(OH)₂ ⇒ Ba²⁺ + 2OH⁻(b=valence=2)
[OH⁻]= 2 . 0.054
[OH⁻] = 0.108
pOH= - log 0.108
pOH=0.967
pOH+pH=14
pH=14-0.967
pH=13.033
Which intermolecular force would affect the boiling point the least?
Answer: Van der Waals forces
Explanation: trust me i tried the other dudes answer and I got it wrong.
The intermolecular force that would affect the boiling point the least is ionic bonding. The correct option is C.
Strong electrostatic interaction between ions that are positively and negatively charged is referred to as ionic bonding.
It takes place when two atoms with vastly differing electronegativities are in close proximity to one another, leading to the transfer of electrons from one atom to another to create ions.
Although ionic compounds have high melting and boiling temperatures, intermolecular forces are less important than the strong attraction between the ions in the solid state.
In contrast, neutral molecules or atoms experience intermolecular forces such as hydrogen bonds, dipole-dipole interactions, and Van der Waals forces (which include dispersion forces).
The boiling points of substances are greatly influenced by these factors.
Thus, the correct option is C.
For more details regarding intermolecular forces, visit:
https://brainly.com/question/9328418
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EZ POINTS!!!
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..!!!!!
A 0.200 M NaOH solution was used to titrate a 18.25 mL HF
solution. The endpoint was reached after 31.20 mL of titrant
were added. Find the molar concentration of the original HF
solution.
The molar concentration of the original HF solution : 0.342 M
Further explanationGiven
31.2 ml of 0.200 M NaOH
18.2 ml of HF
Required
The molar concentration of HF
Solution
Titration formula
M₁V₁n₁=M₂V₂n₂
n=acid/base valence (amount of H⁺/OH⁻, for NaOH and HF n =1)
Input the value :
[tex]\tt 0.2\times 31.2\times 1=M_2\times 18.25\times 1\\\\M_2=0.342[/tex]