Answer:
There are 0.379 moles of Ca in the given sample.
Explanation:
Hey there!
We're given that we have 15.2 grams of Ca (Calcium). We need to convert grams to moles.
There are many different conversion types for moles. A few examples are:
grams to molesmoles to gramsgrams to particlesmoles to litersThere are really endless possibilities for conversion factors. Since we want to find the number of moles in a certain sample, we first need to define what a mole is.
Mole - a unit of measurement in chemistryA mole is one unit of a certain item. For instance, one cup would be equivalent to one mole. Moles are simply a hypothetical unit in chemistry that act as a placeholder.
Now, how do we find the number of moles?
We know that a mole of something is one of that substance. In this case, we're referring to one atom of Calcium.
Therefore, we need to reference a periodic table to understand what the mass of one atom of calcium is equivalent to. I'll be using the official AP Chemistry periodic table as issued by the College Board.
When we reference the periodic table, we see the mass of one atom of calcium is equivalent to 40.08 amu (atomic mass units).
We learn in chemistry that we can use the terms amu and grams interchangeably, so we have learned that one mole of calcium is equivalent to 40.08 grams.
How do we work this out?
Now, we need to find out how many moles are in 15.2 grams of calcium. We can use dimensional analysis to work this out.
Our starting unit will be 15.2 grams of Ca.
[tex]\text{15.2 grams Ca}[/tex]We want to convert this into moles, so we need to cancel out our grams value. Additionally, since we know that we have 40.08 grams of Ca in one mole, we can set these up as two ratios:
[tex]\displaystyle \frac{\text{40.08 grams Ca}}{\text{1 mole Ca}}[/tex][tex]\displaystyle \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]These ratios can be used to express the relationship between the moles of calcium and the mass of one calcium atom. However, we need our value of grams to cancel out, so since we will be using cross multiplication in our dimensional analysis, we need to use the ratio with grams on the bottom.
Now that we have selected our ratio, we can set up a multiplication problem of our two ratios:
[tex]\displaystyle \text{15.2 grams Ca} \times \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We assume that we have a denominator of 1 below 15.2 grams Ca.
Now, we perform our multiplication.
[tex]\displaystyle \frac{\text{15.2 grams Ca} \ \times \ \text{1 mole Ca}}{\text{40.08 grams Ca}}[/tex]
We see that our remaining unit is going to be mole(s) Ca, so we can go ahead and drop our grams Ca unit.
[tex]\displaystyle \frac{\text{15.2} \ \times \ \text{1 mole Ca}}{\text{40.08}}[/tex]
Now, we need to simplify a little bit.
[tex]\displaystyle \frac{\text{15.2}}{\text{40.08}} = \text{? moles Ca}[/tex]
Finally, let's divide our fraction and evaluate our equation to find the value of moles Ca.
[tex]\displaystyle \frac{15.2}{40.08} = \text{0.379241517 moles Ca}[/tex]
Are we done yet?
Not just yet! To complete our work, we need to find the number of significant figures we can use. We are given two values in which we can use to judge how many significant figures we are limited to.
15.2 -- Three significant figures40.08 -- Four significant figuresIn chemistry, we always use the least number of significant figures for precision calculations, so we need to round our answer to three significant figures.
[tex]0.379241517 \approx 0.379[/tex]
Therefore, there are approximately 0.379 moles of Ca in the given sample.
4
In the Hatom , what is the correct order (arrangement) of energy levels
Which of these is a disadvantage of wind energy?
a. it is renewable.
0
b. it reduces greenhouse gas emissions.
0
c. it is abundant.
0
d. it reduces bird and bat populations
Answer: d
Explanation: took the test got it right
A] 1 N2 + 3 H2 → 2 NH3
1. How many moles and grams of ammonia can be made from 6.3 moles of H2 ?
2. How many moles and particles of ammonia can be made from 2.5 moles of N2 ?
3. How many moles is 425 g of ammonia? How many moles and grams of N2 are needed to make it?
4. How many moles and grams and liters of H2 are needed to make 10 moles of ammonia?
I haven't done these in some time, so I'm not sure if they are 100% right.
1) 6.3 moles of H2( 2 mol of NH3 / 3 mol of H2)= 4.2 mol of NH3
6.3 moles of H2( 2 mol of NH3/ 3 mol of H2)(17.04 g of NH3/1 mol NH3)= 71.57 g of NH3
2) 2.5 moles of N2(2 mol of NH3/1 mol of N2)= 5 moles of NH3
2.25 moles of N2(2 mol of NH3/ 1 mol of N2)(6.02x10^23 particles/ 1 mol of NH3)= 3.01x10^24 particles of NH3
3) 425 g of NH3(1 mol of NH3/17.04 g NH3)= 24.9 moles of NH3
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)(28.02 g of N2/1 mol N2)= 349 g of N2
425 g of NH3(1 mol of NH3/17.04 g of NH3)(1 mol of N2/2 mol of NH3)= 12.5 mol of N2
4) 10 moles NH3(3 moles of H2/2 moles of NH3)= 15 moles H2
10 moles NH3(3 mol of H2/2 mol of NH3)(2.02 g of H2/1 mol of H2)= 30.3 g of H2
30.3 g = .0303 liters of H2
Write a word equation and a skeleton equation for the chemical reaction.
A. Solid iron reacts with aqueous copper(ii) nitrate to produce solid copper and aqueous iron(ii) nitrate.
During a solar eclipse, explain what would an observer
on the Moon see on the surface of the Earth?
Answer:
It getting darker
Explanation:
This is because the light isn't hitting the earth as much, making it darker. They might also see more city lights than before. Hope this helps! plz mark as brainliest!
Which halogens are gases at STP?
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
Answer:
As the atomic number increases, the reactivity of the halogens decreases. Fluorine and chlorine exist as gases at room temperature, while bromine is a liquid, and iodine is a solid.
How many moles of water are produced from burning 80 moles of
methane in excess oxygen?
Answer:
160 mol H₂O
Explanation:
Step 1: Write the balanced complete combustion reaction
CH₄ + 2 O₂ ⇒ CO₂ + 2 H₂O
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of CH₄ to H₂O is 1:2.
Step 3: Calculate the moles of water formed from 80 moles of methane
We will use the previously established molar ratio.
80 mol CH₄ × 2 mol H₂O/1 mol CH₄ = 160 mol H₂O
Use average bond enthalpies (linked above) to calculate the enthalpy change for the following gas-phase reaction. CO(g) + Cl2(g) COCl2(g) To analyze the reaction, first draw Lew To analyze the reaction, first draw Lewis structures for all reactant and product molecules. ΔHreaction = ------ kJ Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures. To analyze the reaction, first draw Lewis structures for all reactant and product molecules. Draw the reaction using separate sketchers for each species. Separate multiple reactants and/or products using the + sign from the drop-down arrow. Separate reactants from products using the → symbol from the drop-down menu. Remember to include nonbonding valence electrons in your Lewis structures.
Answer:
ΔHreaction (KJ) = - 78 KJ
The value may vary in relation to the source of the bond enthalpy data.
Bond enthalpies used (From a table of bond enthalpies )
Bond KJ/ mol
C≡O 1080
C-Cl 330
C=O 741
Cl-Cl 243
Explanation:
CO(g) + Cl2(g) → COCl2(g)
1) Lewis structures
Valence electrons
C 4
O 6
Cl 7
Reactants
CO(g)
In the case of CO, carbon has a negative charge and oxygen a positive charge.
Cl2(g)
Products
COCl2(g)
_______________________
ΔHreaction (KJ) = ∑ n* ΔH ( reactants) - ∑ n* ΔH (product)
ΔHreaction (KJ) = (ΔHC≡O + ΔHCl-Cl) - ( ΔHC=O + 2* ΔHC-Cl)
Replacing the values
ΔHreaction (KJ) = (1080 + 243) - ( 741 + 2* 330)
ΔHreaction (KJ) = 1323 - 1401
= - 78 KJ
You are given 19.2 liters of H3PO4. How many moles do you have?
Answer:
Explanation:
Do a quick conversion: 1 grams H3PO4 = 0.010204583427424 mole using the molecular. How many grams H3PO4 in 1 mol? You can view more details on each measurement unit: molecular weight of H3PO4 or mol This. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.
Which sample contains the greatest number of atoms. A sample of Ca that contains 3.40×1024 atoms or a 1.76 mole sample of Be?
The sample of _____ contains the greatest number of atoms.
Answer:
The sample of __Ca___ contains the greatest number of atoms
Explanation:
As we know,
1 mole [tex]= 6.022*10^{23}[/tex] molecular entities (Can be atom, ions or molecules)
Number of atoms in 1.76 mole sample of Be
[tex]= 6.022*10^{23} *1.76\\= 1.059 * 10^{24}[/tex]
The sample of __Ca___ contains the greatest number of atoms
Help me pls I put 49 point( every single point that I have) pls help me
Answer:
see below
Explanation:
1) chem rxn compound molecule covalent ions ionic
2) 2 hydrogen one oxygen H2O covalent
3) is always liq
how much carbon is in CO2 if the sample contains 48 g of oxygen remember the ratio of carbon to oxygen is 12 g of 32 g
18g
24g
12g
20g
Answer: 24g
Explanation:
What is created when an acid is mixed with a base?
Answer:
If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution.
help ill mark brainlist !!! (no bots or links)
at a subduction zone, a very low and deep point forms on the surface of the crust. what is this low point called?
A ) Rift
B ) Valley
C ) Ridge
D ) Trench
Answer:
The trench.
Explanation:
A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex.
write the molecular formula of sodium nitroprusside.
Answer:
Explanation: Sodium Nitroprusside, whose molecular formula is • 2H2O, and whose molecular weight is 297.95. Dry sodium nitroprusside is a reddish-brown powder, soluble in water.
pls help with 1 question (15 ponts)
What happens in the circulatory system?
Explain the term mole ratio in your own words When would you use this term ?
Answer:
A mole ratio is the ratio between the amounts in moles of any two compounds involved in a chemical reaction.
Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
Explanation:
what statement is the best description of a chemical bond
Answer:
A chemical bond holds atoms together.
SSA PRACTICE QUESTION
Mandy wanted to see if a new
environmentally-friendly pesticide will
prevent insect damage to tomato plants.
After making a hypothesis, she conducts
her experiment. She treats five tomato
plants with traditional pesticide and five
with the new pesticide. Mandy also
leaves five plants untreated as a control.
She makes careful notes of how she set
up her experiment and then records her
data about all of the plants. Why is it
important for Mandy to record her
procedures and data accurately?
Answer:
The correct answer is - so that other scientists can replicate the experiment and make sure the results are correct or to check accuracy.
Explanation:
The data and procudres are required to be recorded or noted correctly so the experiment and research can be replicate and tested for the accuracy of the experiment by other scientist and researcher.
Mandy also need to note procedure, data, variables and other data correctly for the testing the accuracy and replication of the experiment. The replication is essential to check if every thing is correct and result are error free.
PbSO4 has a Ksp = 1.3 * 10-8 (mol/L)2.
I will mark brainliest if you answer all three questions. Thank you so so so much!!!
i. The dissolution of PbSO₄ in water entails its ionizing into its constituent ions:
[tex]\mathrm{PbSO_{4}}(aq) \rightleftharpoons \mathrm{Pb^{2+}}(aq)+\mathrm{SO_4^{2-}}(aq).[/tex]
---
ii. Given the dissolution of some substance
[tex]xA{(s)} \rightleftharpoons yB{(aq)} + zC{(aq)}[/tex],
the Ksp, or the solubility product constant, of the preceding equation takes the general form
[tex]K_{sp} = [B]^y [C]^z[/tex].
The concentrations of pure solids (like substance A) and liquids are excluded from the equilibrium expression.
So, given our dissociation equation in question i., our Ksp expression would be written as:
[tex]K_{sp} = \mathrm{[Pb^{2+}] [SO_4^{2-}]}[/tex].
---
iii. Presumably, what we're being asked for here is the molar solubility of PbSO4 (at the standard 25 °C, as Ksp is temperature dependent). We have all the information needed to calculate the molar solubility. Since the Ksp tells us the ratio of equilibrium concentrations of PbSO4 in solution, we can consider either [Pb2+] or [SO4^2-] as equivalent to our molar solubility (since the concentration of either ion is the extent to which solid PbSO4 will dissociate or dissolve in water).
We know that Ksp = [Pb2+][SO4^2-], and we are given the value of the Ksp of for PbSO4 as 1.3 × 10⁻⁸. Since the molar ratio between the two ions are the same, we can use an equivalent variable to represent both:
[tex]1.3 \times 10^{-8} = s \times s = s^2 \\s = \sqrt{1.3 \times 10^{-8}} = 1.14 \times 10^{-4} \text{ mol/L}.[/tex]
So, the molar solubility of PbSO4 is 1.1 × 10⁻⁴ mol/L. The answer is given to two significant figures since the Ksp is given to two significant figures.
Suppose that Laser A were to shine a beam of light straight into the left side of Prism A, and Laser B were to shine an identical beam of light straight into the left side of Prism B. Which prism would refract the light more? (Assume the sides of the two prisms are sloped the same.)
Answer:
Prism B
Explanation:
Pls help with the question.
Answer:
2 L
Explanation:
From the question
Applying boyles law,
PV = P'V'....................... Equation 1
Where P = Initial pressure, P' = Final Pressure, V = Initial Volume, V' = Final Volume.
make V' the subject of the equation
V' = PV/P'.................... Equation 2
Givne: V = 5 L, P = 500 mmHg, P' = 1240 mmHg
Substitute these values into equation 2
V' = (5×500)/1240
V' = 2500/1240
V' = 2 L
2 C4H10 + 13O2 -------> 8CO2 + 10H2O
a) What is the mole ratio between butane and oxygen gas?
b) What is the mole ratio between water and oxygen gas?
c) How many moles of water formed?
d) How many moles of butane burned?
e) How many grams of butane burned?
f) How much oxygen was used up in moles?
g) How much oxygen was used up in grams?
Answer:
A. 2 : 13
B. 10 : 13
C. 10 moles of water, H₂O.
D. 2 moles of butane, C₄H₁₀
E. 116 g of butane, C₄H₁₀
F. 13 moles of oxygen, O₂
G. 416 g of oxygen, O₂
Explanation:
The equation for the reaction is given below:
2C₄H₁₀ + 13O₂ —> 8CO₂ + 10H₂O
A. Determination of the mole ratio between butane and oxygen gas.
Mole of butane, C₄H₁₀ = 2 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of butane and oxygen = 2 : 13
B. Determination of the mole ratio between water and oxygen gas
Mole of the water, H₂O = 10 moles
Mole of oxygen, O₂ = 13 moles
Mole ratio of water and oxygen = 10 : 13
C. Determination of the moles of water formed.
From the balanced equation above,
10 moles water, H₂O were produced.
D. Determination of the moles of butane burned.
From the balanced equation above,
2 moles of butane, C₄H₁₀ were burned.
E. Determination of the mass of butane burned.
Molar mass of C₄H₁₀ = (12×4) + (10×1)
= 48 + 10 = 58 g/mol
Mole of C₄H₁₀ = 2 moles
Mass of C₄H₁₀ =?
Mass = mole × molar mass
Mass of C₄H₁₀ = 2 × 58
Mass of C₄H₁₀ = 116 g
Thus, 116 g of butane, C₄H₁₀ were burned.
F. Determination of the number of mole of oxygen used.
From the balanced equation above,
13 moles of oxygen, O₂ were used.
G. Determination of the mass of oxygen used.
Molar mass of O₂ = 2 × 16 = 32 g/mol
Mole of O₂ = 13 moles
Mass of O₂ =?
Mass = mole × molar mass
Mass of O₂ = 13 × 32
Mass of O₂ = 416 g
Thus, 416 g of oxygen, O₂ were used.
How many grams of carbon disulfide will be produced if .012
kg of sulfur reacts with carbon?
Answer:
14.25g
Explination:
I found this answer on quizlet titled, "Chem Quizlet" by jamie_barbara
Select all of the answers that apply.
Which of the following characteristics must an air mass have?
It flows as one unit.
It has different temperatures but uniform humidity.
It must be 1,000 miles or more in size.
It must form over a low-pressure area.
It has a uniform temperature and humidity.
Explanation:
it has different temperature but uniform humidity
hope it will help you
What does H2o mean in chemistry?
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Answer:
Water (chemical formula: H2O) is a transparent fluid which forms the world's streams, lakes, oceans and rain, and is the major constituent of the fluids of organisms. As a chemical compound, a water molecule contains one oxygen and two hydrogen atoms that are connected by covalent bonds.
<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3
How did you spend your Easter?
Answer:
I didn't do anything, we don't celebrate lol I hope you had fun though!
Explanation:
In 2-3 sentences, explain how objects in our solar system planets acquired the mass to become planets.
The sun contained 99% of the available matter and the rest matter formed smaller clumps inside the spinning disk. These clumps gained enough mass which lead to their gravity shaping them into spheres becoming planets.
What are planets?A planet can be described as a large, rounded astronomical body that is neither a star nor its remnant. The theory of planet formation is the nebular hypothesis, which tells that an interstellar cloud collapses out of a nebula to generate a young protostar orbited by a protoplanetary disk.
The planet grows in this disk by the accumulation of material driven by gravity and this process is known as accretion. Our solar system has at least eight planets that rotate around an axis tilted with respect to its orbital pole.
All planets possess an atmosphere, although that of Mercury is tenuous. The Solar System planets create magnetic fields apart from Venus and Mars, and all planets except Venus and Mercury have natural satellites.
Learn more about planets, here:
https://brainly.com/question/15268075
#SPJ2
The strength of an acid is affected by the polarity of the bond connected to the acidic hydrogen. The more highly polarized this bond, the more easily the hydrogen is ionized. Electronegative atoms or groups of atoms present in the structure of an acid can act to withdraw electrons and produce additional polarization. Two common groups of acids to which this principle can be applied are oxoacids and carboxylic acids. In the latter group, the length of the hydrocarbon chain in a carboxylic acid has very little effect on acid strength Longer chains may slightly diminish acidity. Bases act as hydrogen ion acceptors because of the unshared electron pass in their structure. Any group present in a base that withdraws electrons makes these electron pairs less available to accept a hydrogen ion. In contrast, any group that can act as an electron donating group such as hydrocarbon groups (usually represented as II) can increase the base strength. Thus, the addition of electronegative atoms or groups of atoms to the structure of a base decreases the base strength and electron donating groups increase base strength. Many common weak bases are derivatives of ammonia, in which H atom(s) of NH_2 are replaced with other groups.
Arrange the following oxoacids in order of decreasing acid strength. Rank from strongest to weakest acid.
1. HBrO
2. HClO
3. HClO2
4. HClO3
Answer:
The answer is "[tex]\bold{HClO_3 > HClO_2 >HClO > HBrO}[/tex]"
Explanation:
We arrange oxoacids to decrease the intensity of acids in this question. Or we may conclude all this from strongest to weakest acids they order oxoacids, that's why above given order is correct.
3. Calculate the average atomic mass of sulfur if 95.00% of all sulfur atoms have
a mass of 31.972 amu, 0.76% has a mass of 32.971u and 4.22% have a mass of
33.967u.
Answer:
Average atomic mass = 32.057 u
Explanation:
Average atomic mass = Σ(isotope × abundance)
Average atomic mass = (0.95 × 31.972) + (0.0076 × 32.971) + (0.0422 × 33.967)
Average atomic mass = 32.057 u