Answer:
I think its false im not sure
Explanation:
A sample of hydrate sodium carbonate has a mass of 71.5 g. after heating, the anhydrous sodium carbonate has a mass of 26.5 grams. Calculate the % water.
Answer:
62.9%
Explanation:
Step 1: Given data
Mass of hydrate sodium carbonate (mNa₂CO₃.xH₂O): 71.5 gMass of anhydrous sodium carbonate (mNa₂CO₃): 26.5 gStep 2: Calculate the mass lost of water
We will use the following expression.
mH₂O = mNa₂CO₃.xH₂O - mNa₂CO₃
mH₂O = 71.5 g - 26.5 g = 45.0 g
Step 3: Calculate the percent of water in the hydrate sodium carbonate
We will use the following expression.
%H₂O = mH₂O / mNa₂CO₃.xH₂O × 100%
%H₂O = 45.0 g / 71.5 g × 100%
%H₂O = 62.9%
A certain ore is 37.3 % nickel by mass. How many kilograms of this ore would you need to dig up to have 65.0 g of nickel
Answer:
0.174kg of Ore are required
Explanation:
The ore of 37.3% in nickel by mass means that in 100g of ore there are 37.3g of nickel. As we need to obtain 65g of nickel we can convert this mass to mass of ore using the conversion factor (100g Ore / 37.3g Nickel) as follows:
65g of nickel * (100g Ore / 37.3g Nickel) = 174g of Ore are needed to have 65.0g of nickel. In kilograms:
174g Ore * (1kg / 1000g) =
0.174kg of Ore are requiredWhich statement describes how the sun gets its light?
A. It bends light.
B. It reflects light.
C. It refracts light.
D. It makes its own light.
Answer:
D
Explanation:
it's a star it has gas and makes it own light
Explain how the direction of the arrow in the bond dipole symbol ( ) relates to the elec-tron density and the partial charges.
The complete question is shown in the image attached
Answer:
See explanation
Explanation:
In a molecule, the direction of the dipole moment also shows the direction of the shift in electron density. Let me give you an instance. In HCl, the dipole points towards the chlorine atom. This implies that the bond is polar and the chlorine atom accommodates the greater share of the electron density of the H-Cl bond. The negative partial charge rests on the more electronegative atom (chlorine in this case) while the partial positive charge rests on the more electropositive atom(hydrogen in this case). Recall that the difference in electron density between the two atoms creates this polarity.
Having said that much, let me come to the issue of electronegativity and bond polarity. The polarity of bonds depends on the electronegativity difference between atoms. I have just established that the H-Cl bond is polar owing to the difference in electronegativity between hydrogen and chlorine. If I replace the chlorine atom in the molecule with another hydrogen atom, the molecule is no longer polar because the difference in electronegativity of a H-H bond is zero.
Lastly, let me talk about electronegativity difference and bond character. The magnitude of electronegativity difference between atoms determines the bond character. If the electronegativity difference between bonding atoms is;
less than 0.4, the bond is a pure covalent bond
between 0.4 - 1.8, the bond is a polar covalent bond
greater than 1.8, the bond is a pure ionic bond
What one word completes the
If a plant is losing water faster than it can be replaced by its roots, its stomata will
sentence?
Answer:
it causes the cells to become flaccid and the stomata openings to close
Explanation:
the stomata closes to reduce water loss
When a plant is losing water at a greater rate than it can be replaced by its roots, then in such a case, the stomata will get close to reduce the loss of water.
• Generally, the opening of stomata takes place in the day and gets close at night. To prevent the loss of water stomata get close during the night.
• However, in certain cases, even during the day, when the plant experiences loss of water due to conditions like drought then stomata remain close during the day also.
• This opening and closing of stomata take place as a response to the signals from the external environment.
Therefore, when more amount of water is loosing from the plant than getting absorbed by the roots, the stomata gets the signal to remain close to prevent water loss and death of the plant.
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What is the molar mass of magnesium sulfate, MgSO4?
Answer:
120.37 g/mol is the molar mass of magnesium sulfate
Which correctly lists three characteristics that are used to describe air?
O Altitude, density, radiation
O Density, radiation, mass
O mass, pressure, density
O pressure, altitude, radiation
Answer:
Mass Pressure and density.
Explanation:
which an element that exist into two form
Answer:
Sulphur
Explanation
Rhombic and monoclinic sulphur are its allotropic forms
What is the direct democracy? Does it work well with a large or small population
Answer:
In a direct democracy, which is also called pure democracy the decisions are not taken by representatives. All decisions are voted on by the people. When a budget or law needs to be passed, then the idea goes to the people. Large governments rarely make decisions this way
Explanation:
I don't think direct democracy works well unless the population is homogenous and agree on major issues
Suppose that you take a sample of 500 g of ocean water and let the water evaporate. The mass of the remaining salts is 17 g. What was the salinity of the ocean water
Answer: The salinity of ocean water is 34 ppt.
Explanation:
Salinity is defined as the number of grams of salts present per kilogram of seawater. It is expressed in parts per thousand.
The formula used to calculate the salinity of ocean water or sea water is:
[tex]\text{ Parts per thousand}=\frac{\text{Mass of salts}}{\text{Mass of sea water}}\times 1000[/tex]
We are given:
Mass of salts = 17 g
Mass of sea water = 500 g
Putting values in above equation, we get:
[tex]\text{ Parts per thousand}=\frac{17g}{500g}\times 1000\\\\\text{ Parts per thousand}=34[/tex]
Hence, the salinity of ocean water is 34 ppt.
c5h12 compound name
The density of a pure substance is its mass per unit volume. The density of ethylene glycol has been measured to be 1097.gL. Calculate the mass of 405.mL of ethylene glycol. Be sure your answer has a unit symbol and the correct number of significant digits.
Answer: The mass of 405 mL of ethylene glycol is 444.3 g.
Explanation:
Density is defined as the mass contained per unit volume.
[tex]Density=\frac{mass}{Volume}[/tex]
Given :
Density of the ethylene glycol= [tex]1097g/L[/tex]
Volume of the ethylene glycol= [tex]405ml[/tex] = 0.405 L (1L=1000ml)
Mass of the ethylene glycol = ?
Putting in the values we get:
[tex]1097g/L=\frac{x}{0.405L}[/tex]
[tex]x=444.3g[/tex]
Thus the mass of 405 mL of ethylene glycol is 444.3 g
Write a balanced chemical equation depicting the formation of one mole of H2O2(g) from its elements in their standard states.
Answer:
[tex]H_2(g)+O_2(g)\rightarrow H_2O_2(g)[/tex]
Explanation:
Hello!
In this case, since the formation reaction of a compound is undergone when the pure elements composing it are combined, for gaseous hydrogen peroxide, gaseous diatomic hydrogen and oxygen (standard state) must be combined in order to obtain the gaseous hydrogen peroxide as shown below:
[tex]H_2(g)+O_2(g)\rightarrow H_2O_2(g)[/tex]
Whereas it is proved there are two hydrogen and oxygen atoms at each side of the chemical equation and therefore it is balanced.
Best regards!
Give an example of chemical reaction that occurs in everyday life
Answer: metal and salt water
Explanation: salt starts to brake down metal and metal is everywhere in the ocean hope this helps
Answer:
baking a cake.
Explanation:
baking a cake is an example of a chemical reaction that happens daily because a new substance is forming when the cake is being baked. hope this helps! :)
675 g of carbon tetrabromide is equivalent to how many
mol. Make sure to round your answer to the nearest WHOLE NUMBER
2.04 mol CBr₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Organic
Writing Organic CompoundsWriting Covalent CompoundsOrganic PrefixesAtomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
675 g CBr₄
Step 2: Identify Conversions
Molar Mass of C - 12.01 g/mol
Molar Mass of Br - 79.90 g/mol
Molar Mass of CBr₄ - 12.01 + 4(79.90) = 331.61 g/mol
Step 3: Convert
[tex]\displaystyle 675 \ g \ CBr_4(\frac{1 \ mol \ CBr_4}{331.61 \ g \ CBr_4}) = 2.03552 \ mol \ CBr_4[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
2.03552 mol CBr₄ ≈ 2.04 mol CBr₄
Answer:
[tex]\boxed {\boxed {\sf About \ 2.04 \ moles \ of \ CBr_4}}[/tex]
Explanation:
1. Define Formula
The compound is carbon tetrabromide. The tetra indicates 4 atoms of bromine.
Carbon (C)+ 4 Bromine (Br) = CBr₄2. Find Molar Mass
There are 2 elements in this compound: carbon and bromine. Use the Periodic Table to find the molar masses of these elements.
Carbon (C): 12.011 g/mol Bromine (Br): 79.90 g/molThe molar mass is based on the number of atoms in the compound. The compound has 1 atom of carbon and 4 atoms of bromine.
CBr₄= 1(12.011 g/mol) + 4(79.90 g/mol)
= 12.011 g/mol+319.60 g/mol = 331.611 g/mol
3. Convert Grams to Moles
We want to convert 675 grams to moles. We should use the molar mass as a fraction.
[tex]\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]
Multiply by the given number of grams.
[tex]675 \ g \ CBr_4 *\frac{331.611 \ g \ CBr_4}{1 \ mol \ CBr_4 }[/tex]
Flip the fraction so the grams of CBr₄ will cancel.
[tex]675 \ g \ CBr_4 *\frac{1 \ mol \ CBr_4 }{331.611 \ g \ CBr_4}[/tex]= [tex]675 \ *\frac{1 \ mol \ CBr_4 }{331.611 \ }[/tex]
[tex]\frac{675 \ mol \ CBr_4 }{331.611 \ }[/tex] = [tex]2.03551752 \ mol \ CBr_4[/tex]
4.Round
The original measurement, 675 grams has 3 significant figures (6,7 and 5), so our answer must have the same.
For the answer we found, 3 sig figs is the hundredth place.
[tex]2.03551752 \ mol \ CBr_4[/tex]
The 5 in the thousandth place tells us to round the 3 to a 4.
[tex]\approx 2.04 \ mol \ CBr_4[/tex]
There are about 2.04 moles of carbon tetrabromide in 675 grams.
How many moles in 206.91 g Na
Answer:
The answer is 9.000090040048176
Is burning physical or chemical change?
Answer:
a chemical change
Explanation:
lighting a match is a chemical change. chemical reactions cause chemical change. in a chemical reaction two or more substances, called the reactants, form different substances called products. hope this helped :)
How many protons, neutrons, and electrons does S^2- have
Answer:
The protons and electrons in each element are equal. The sulfur has 16 electrons and 16 protons. But the ionic atom's electron quantity changes depending on how many it has gained. 'S2-' has gained 2 electrons, which means it has now 18 electrons and 16 protons. 16 neutrons
Explanation:
pleaseeee helpppp thank youu
Answer:
Answer: wellb. a type of gas is evolved ( hydrogen gas )
which animal takes on the temperature of their surroundings and does not use food energy to keep warm
please help..............
Answer:
hope this help
Explanation:
change: volume of solid , volume of liquid , the volume of gases
not change: the shape of solid , the shape of liquid , the shape of gases
How do cells prepare for sexual reproduction?
A. Punnett Square B. Meiosis C. Mendel D. Trait
Answer:
Meiosis
Explanation:
They just split in four.
Question 9 of 10
What is stoichiometry used for?
A. Calculating the mass of a product from the number of moles of
B. Calculating the molarity of the limiting reagent used in a reaction
DC. Calculating the actual yield of a product in a chemical reaction
D. Calculating the weighted average atomic mass of an element
reactants
Stoichiometry is used for calculating the mass of a product from the number of moles of reactants. The correct option is A.
What is stoichiometry?
Stoichiometry is made up of two words, stoikhein, which means element, and metron, which means measure. Stoichiometry is a method of determining the data by using the knowledge of reactants and products.
There are five steps of stoichiometry that are the following:
Obtain all measurement information from the task.Change all measuring units to the same base units.Compose a thoughtful response.Ascertain the species' stoichiometry.Calculate the appropriate quantity in step five.Thus, the correct option is A. Calculating the mass of a product from the number of moles of reactant.
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why are concerns like safety and recycling important in astronomy
Answer:
Keep the world safe and clean
Explanation:
safety = keep people inline and help them from making bad decisions
clean = keep the world from being polluted or trashy
Astronomy deals with the study of celestial objects such as moon, stars, sun, planets, etc.
Safety is the art of being protected from danger
Recycling is the process of waste conversion. That is, useful materials are generated from wastes.
Astronomers, in their exploration of extraterrestrial bodies, need to ensure that proper measures are taken to ensure their safety in these locations. Unhealthy practices such as deforestation and indiscriminate waste disposal may cause environmental hazards such as global warming. This is a threat to the atmosphere.
Therefore, wastes have to be converted to reusable products to discourage indiscriminate disposals. Hence the importance of the terms "safety" and "recycling" in astronomy.
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Balance the following chemical equation: N2H4+O2→ NO2+H2O
Answer:
N2H4 + 3O2 → 2NO2 + 2H2O
Explanation:
What is the difference between an atomic symbol and a chemical symbol?
Answer: A chemical symbol is a one- or two-letter designation of an element. Compounds are combinations of two or more elements. A chemical formula is an expression that shows the elements in a compound and the relative proportions of those elements.
Group IA elements are very reactive metal . why
Answer:
Alkali metals are among the most reactive metals. This is due in part to their larger atomic radii and low ionization energies. They tend to donate their electrons in reactions and have an oxidation state of +1. ... All these characteristics can be attributed to these elements' large atomic radii and weak metallic bonding.
Explanation:Because they have just one valence electron, group 1 elements are very reactive. As a result, they are found in nature only in combination with other elements. Alkali metals are all solids at room temperature. ... From the top to the bottom of group 1, the elements have heavier, more reactive atoms.
hope it helped :)
A Gold ring is a what?
Element
Compound
Colloid
Alloy
Answer: Alloy
Explanation: gold is an alloy, or mixture of metals
The atomic masses of 35Cl (75.53 percent) and 37Cl 17 17 (24.47 percent) are 34.968 amu and 36.956 amu, re- spectively. Calculate the average atomic mass of chlorine. The percentages in parentheses denote the relative abundances.
Explanation:
the average atomic mass of chlorine= (34.968 x 0.7553) + ( 36.956 x 0.2447) = 35.4545
Ca % = 100x (5 x 40/502 ) = 39.84 % ( where 502 is molar mass of comp)
P% = 3 x 30.97367 x 100/502 = 18.51 %
O % = (100x13x16)/502 = 41.434
H % = 100-39.84-18.51-41.434 = 0.216 %
% Ca = 100 x40/( 116) = 34.483 %
% Si = 100 x28/116 = 24.14 %
% O = 100-34.483-24.14 = 41.38 %
if x-2 is a factor of x^m - 3x^m-1 +4x-4,find the value of m.
Explanation:
By Factor Theorem,
(2)^m - 3(2)^(m-1) + 4(2) - 4 = 0.
=> 2^m - 1.5 * 2^m + 4 = 0
=> 4 - 0.5 * 2^m = 0
=> 0.5 * 2^m = 4
=> 2^m = 8
=> m = 3.
Hence the value of m is 3.