What is the percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it?
Answer: The percent by mass concentration is 33.3 %
Explanation:
Mass percent is the ratio of mass of solute to the mass of solution in terms of percentage.
mass of solute = 50 g
mass of solution = [tex]{\text {density of solution}}\times {\text {volume of solution}}=1.5g/ml\times 1000ml=1500g[/tex]
Mass percentage = [tex]\frac{50g}{1500g}\times 100\%=33.3\%[/tex]
Thus percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it is 33.3 %
What causes polar bonds
Answer:
Bonds are polar when one element in a compound is more electronegative than the other. This creates a dipole in the molecule where one end of the molecule is partially positive and one end is partially negative
Explanation:
What would be the oxidation number of the atoms in these compounds?
Answer:
Oxidation state] is defined as the charge an atom might be imagined to have when electrons are counted according to an agreed-upon set of rules:
The oxidation state of a free element (uncombined element) is zero for a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion.
Hydrogen has an oxidation state of 1 and oxygen has an oxidation state of −2 when they are present in most compounds. (Exceptions to this are that hydrogen has an oxidation state of −1 in hydrides of active metals, e.g. LiH, and oxygen has an oxidation state of −1 in peroxides, e.g. H2O2 the algebraic sum of oxidation states of all atoms in a neutral molecule must be zero, while in ions the algebraic sum of the oxidation states of the constituent atoms must be equal to the charge on the ion.
The same is written in my textbook. But how am I supposed to find the ox. number of an atom, which is in compound like K2UO4?
B.Use the words inside the box to complete the chart below
Answer:
Answered below
Explanation:
>> ice is solid
>> water is liquid
>> Steam is gas
>> Ice → water = melting
>> water → steam = evaporation
>> steam → water = condensation
>> water → ice = freezing
Most of the matter making up the earth is composed of
A. gases
B. compounds
C. mixtures
Most of the matter making up earth is composed of compounds. I think
why is the absolute dating of rocks important?
Answer:
The dating of rocks is important because:
Explanation:
its important to know how the rocks have changed.
The process by which sand is formed from rocks are...
Question 1 options:
melting and cooling
compaction and cementation
heat and pressure
weathering and erosion
Answer:
weathering and erosion
Explanation:
Sand forms when rocks break down from weathering and eroding over thousands and even millions of years. Rocks take time to decompose, especially quartz (silica) and feldspar. Often starting thousands of miles from the ocean, rocks slowly travel down rivers and streams, constantly breaking down along the way.
Answer:
weathering and erosion
b) How many moles of Na2O can be produced from 13.5 moles Na?
Answer: 6.75 moles of [tex]Na_2O[/tex] can be produced from 13.5 moles Na
Explanation:
The balanced chemical equation for formation of [tex]Na_2O[/tex] from Na is:
[tex]4Na+O_2\rightarrow 2Na_2O[/tex]
According to stoichiometry :
4 moles of Na give = 2 moles of [tex]Na_2O[/tex]
Thus 13.5 moles of [tex]Na[/tex] give =[tex]\frac{2}{4}\times 13.5=6.75moles[/tex] of [tex]Na_2O[/tex]
Thus 6.75 moles of [tex]Na_2O[/tex] can be produced from 13.5 moles Na
10. What is the Kinetic Energy of a 100 kg object that is moving with a speed of 13.5 m/s?
Answer:
[tex]100 \times 13.5 = ikw n bahaa[/tex]
IKAW na mag tayms
Pls answer asap! NO ATTACHMENTS!!!
please help :( this is for science.
Chromatogram results are considered to have better resolution if the RF values of the components being separated or further apart rather than closer together
Answer:
False
Explanation:
False : It is better they are closer together
The RF ( retention factor ) is calculated with this formula
= distance travelled / distance travelled by solvent
And the larger the RF factor of a compound the less polar the compound ( i.e. it will not stick to the stationary phase ) hence it is better the RF values of the components to be closer
Answer:
True
Explanation:
The resulting Rf factor, which has no units, is dependent upon the specific stationary and mobile phase used. Chromatogram results are considered to have better resolution if the Rf values of the components being separated are farther apart (e.g. 0.3 and 0.7) rather than closer together (e.g. 0.4 and 0.5). The distance the compound moves relative to the distance the solvent (or mobile phase or eluent) moves is a characteristic of that compound. (where Rf is equal to distance compound moved divided by solvent front distance)
Please help me
Calculate the pH of a 7.75x10^-12 M Hydrobromic acid solution. Ph=______(round to 4sig figs). The solution is?________(acidic/basic)
Answer:
pH = 6.999
The solution is acidic.
Explanation:
HBr is a strong acid, a very strong one.
In water, this acid is totally dissociated.
HBr + H₂O → H₃O⁺ + Br⁻
We can think pH, as - log 7.75×10⁻¹² but this is 11.1
acid pH can't never be higher than 7.
We apply the charge balance:
[H⁺] = [Br⁻] + [OH⁻]
All the protons come from the bromide and the OH⁻ that come from water.
We can also think [OH⁻] = Kw / [H⁺] so:
[H⁺] = [Br⁻] + Kw / [H⁺]
Now, our unknown is [H⁺]
[H⁺] = 7.75×10⁻¹² + 1×10⁻¹⁴ / [H⁺]
[H⁺] = (7.75×10⁻¹² [H⁺] + 1×10⁻¹⁴) / [H⁺]
This is quadratic equation: [H⁺]² - 7.75×10⁻¹² [H⁺] - 1×10⁻¹⁴
a = 1 ; b = - 7.75×10⁻¹² ; c = -1×10⁻¹⁴
(-b +- √(b² - 4ac) / (2a)
[H⁺] = 1.000038751×10⁻⁷
- log [H⁺] = pH → 6.999
A very strong acid as HBr, in this case, it is so diluted that its pH is almost neutral.
1. What is the molar mass of sodium?
11
O
45.90
23
О
16
Answer:
11
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11.
Answer:
22.99g/mol (in this case 23g/mol)
Which substance is the BEST example of a compound?
Orange Juice
Salt Water
Hydrogen
Water
Answer:
I think hydrogen because Hydrogen combined with one atom with oxygen and in hydrogen peroxide. It has two atoms of hydrogen and 2 atoms of oxygen. Therfore it should be a compound.
In a redox reaction,
the oxidizing agent undergoes oxidation
the reducing agent undergoes reduction
the oxidizing agents undergoes reduction
O the oxidizing agent loses electrons
Answer:
the oxidizing agent undergoes oxidation and
the reducing agent undergoes reduction simultaneously
Which of the following metals would be the best to choose for making jewellery? Aluminium, iron, copper or gold?
Answer:
Of course the answer is gold
Explanation:
Gold is used for making jewellery and not aluminium,iron or copper
Answer:
copper or gold.
Explanation:
Copper is also a good material for accessories. Even in the ancient times, those who can’t afford gold jewelry wear copper jewelry instead. It offers design flexibility too due to its high ductility.
what is a pure substance?
Answer:
A pure substance is a substance or an element whose impurities are extracted by concentration by chemical means.
e.g Aluminium is made pure by concentration of it's ore, bauxite by treatment with excess Sodium Hydroxide solution.
determining the molecular formula of a hydrocarbon with a relative molecular mass of 54
Answer:
C₄H₆
Explanation:
A hydrocarbon is a molecule that only contains atoms of Carbon and Hydrogen. As you remember, the molar mass of Carbon is 12g/mol and the molar mass of Hydrogen is 1g/mol.
To solve this question we can find the amount of Carbons necessary that doesn't exceed the 54g/mol. That is:
54g/mol / 12g/mol = 4.5
As the molecular formula must be given in whole numbers, the amount of Carbons is 4. This 4 carbons have a mass of:
12g/mol*4 = 48g/mol
And the hydrogens necessaries to suply the molecular mass are:
54 - 48 = 6 hydrogens
That means molecular formula is:
C₄H₆How many atoms are contained in 12.8 g of Beryllium?
A9.0 atoms
B9.0 x 10 23 atoms
C8.55 atoms
D8.55 x 1023 atoms
Answer:
a atoms
Explanation:
Answer:
C. 8.55 atoms
Explanation:
How many grams is 2.40 x 1023 molecules of N,O,? (5 pts)
PLS HELP ASAP
Answer:
30.26 grams of N₂O₃
Explanation:
Divide by Avogadro's number. This leaves you with the number of moles. Then, multiply by the molar mass of N₂O₃
Based on Reference Table F, which salt is the strongest electrolyte?
1.
CaCO3
2.
Na2SO4
3.
AgCI
4.
Zn3(PO4)2
Answer:
Na2SO4
Explanation:
Na2SO4 dissociates completely in solution to yield ions therefore it is the strongest electrolyte.
The question is incomplete as the table is missing but I will try to explain as generally as possible. Recall that an electrolyte is a compound that conducts electricity in solution.
Also recall that the number of ions available in solution determines the electrolytic strength of a substance. Hence, Na2SO4 dissociates completely in solution to yield ions therefore it is the strongest electrolyte.
Learn more about electrolytes: https://brainly.com/question/1301963
How do I balance
H2O ⇾ H2 + O2
Help please!!! I'll name you brainliest!!
Answer: pls mark brainliest
Explanation: i think so its D
Select the correct answer.
What does an atom gain or lose in an oxidation-reduction reaction?
A.
protons
B.
oxygen
C.
neutrons
D.
electrons
Answer:
D The atom gains an electron in an oxidation-reduction reaction.
Provide a set of step by step instructions to make 750 mL of 1.5 M calcium chloride solution.
Answer: PLease see answer in explanation column
Explanation:
FIRST STEP
We find the grams ( mass ) of solute required to prepare the solution by using the formula
grams ( mass ) of solute, g(CaCl2)= Molar mass x Molarity of the solution x Volume of the solution
Therefore Preparing 750 mL of 1.5 M calcium chloride solution, we have that Molar mass of Calcium chloride =110.98 g/mol
g(CaCl2) =110.98 g/mol X 1.5mol/L X 0.75L
g(CaCl2) =124.8525g CaCl2
SECOND STEP
Now Dissolve 124.8525g CaCl2 in about 350ml of distilled water then add more water until the final volume be comes 750ml
Please help with this
Nuclear changes differ from normal chemical changes in that all nuclear changes
Answer:
(1) Nuclear reactions entail a transition in the nucleus of an atom, which normally results in the formation of a new substance. Chemical reactions, on the other hand, only involve electron rearrangement and do not involve nuclei modifications. (4) Nuclear reactions are unaffected by the element's chemical form.
Explanation:
Hope this helps!
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A 5.0-g sample of Substance X increases in temperature from 20.0°C to 22.0°C when it absorbs 9.6J of heat. What is the specific heat of
Substance X in J/g °C)?
Answer:
0.96 J/g °C
General Formulas and Concepts:
Thermochemistry
Specific Heat Formula: q = mcΔT
m is mass (in grams)c is specific heat (in J/g °C)ΔT is change in temperature, final - initial (in °C)Explanation:
Step 1: Define
[Given] m = 5.0 g
[Given] ΔT = 22.0 °C - 20.0 °C = 2.0 °C
[Given] q = 9.6 J
[Solve] c
Step 2: Solve for c
Substitute in variables [Specific Heat Formula]: 9.6 J = (5.0 g)c(2.0 °C)[Specific Heat] Multiply: 9.6 J = (10. g °C)c[Specific Heat] Isolate c: 0.96 J/g °C = c[Specific Heat] Rewrite: c = 0.96 J/g °CName the following carboxylic
acid:
COOH
A. 1-methylpentanoic acid
B. 2-methylpentanoic acid
C. 1-methylbutanoic acid
D. 5-ethylpentanoic acid
Answer:
methylpentanoic acid,,,,,I guess so
The following carboxylic acid is 2-methylpentanoic acid.
What is a carboxylic acid?A carboxylic acid is an organic compound that contains the carboxyl functional group. The general formula for a carboxylic acid can be abbreviated as R−COOH.
Pentanoic acid can be prepared by reacting a butyl halide with magnesium to obtain a Grignard reagent, which is further reacted with carbon dioxide to give valeric salt.
Hence, the following carboxylic acid is 2-methylpentanoic acid.
Learn more about the carboxylic acid here:
https://brainly.com/question/26855500
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