Answer:
Option A = 1:1
Explanation:
The atoms of calcium and sulphur when react their ration is 1:1. The charge on calcium is +2 and on sulphur is -2.
Ca⁺²S⁻²
The +2 and -2 charges are cancel out and overall charge will be zero.
CaS
so their atomic ratio will be 1:1
Hi!
You would not want to use a stopper when<span> combining two unknown substances because the gasses made from the combination could end up creating to much pressure and explode.</span>
Answer:
0.500 mole of Xe (g) occupies 11.2 L at STP.
General Formulas and Concepts:
<u>Gas Laws</u>
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K
<u>Stoichiometry</u>
- Mole ratio
- Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
<em>Identify.</em>
0.500 mole Xe (g)
<u>Step 2: Convert</u>
- [DA] Set up:
- [DA] Evaluate:
Topic: AP Chemistry
Unit: Stoichiometry
3.0e23 atoms Ne
"E" means 10^
Then we multiply it by a mole of Ne. By the definetion of a mole, it is always 6.022e23 atoms of an element.
So now, we do this:
3.0e23 atoms Ne x (1 mol Ne / 6.022e23 atoms Ne)
After that, we use molar mass. A mole of Neon is equal, in terms of grams, to its avg. atomic mass. This goes true for any element.
It ends up like this:
3.0e23 atoms Ne x (1 mol Ne / 6.022e23 atoms Ne) x (20.1797 g Ne / 1 mol Ne)
Now cancel out the "atoms Ne" and "1 mol Ne"
You end up with a grand total of...
*plugs everything into a calculator*
10.05298... g Ne.
We need to round to 2 sig. figs. (3.0) so now it's....
10 g Ne.
Note that this method can only be used for converting atoms of an element to mass in grams.
Source(s):
A periodic table for the atomic mass of neon.
A chemistry textboook
A chemistry class.
Water (H
2O) is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" [18][19] and the "solvent of life".[20] It is the most abundant substance on Earth[21] and the only common substance to exist as a solid, liquid, and gas on Earth's surface.[22] It is also the third most abundant molecule in the universe.[21]
Water (H
2O)


NamesIUPAC name
water, oxidane
Other names
Hydrogen hydroxide (HH or HOH), hydrogen oxide, dihydrogen monoxide (DHMO) (systematic name[1]), hydrogen monoxide, dihydrogen oxide, hydric acid, hydrohydroxic acid, hydroxic acid, hydrol,[2] μ-oxido dihydrogen
Identifiers
CAS Number
7732-18-5 
3D model (JSmol)
Interactive image
Beilstein Reference
3587155ChEBI
CHEBI:15377 
ChEMBL
ChEMBL1098659 
ChemSpider
937 
Gmelin Reference
117
PubChem CID
962
RTECS numberZC0110000UNII
059QF0KO0R 
InChI
InChI=1S/H2O/h1H2 
Key: XLYOFNOQVPJJNP-UHFFFAOYSA-N 
SMILES
O
Properties
Chemical formula
H
2OMolar mass18.01528(33) g/molAppearanceWhite crystalline solid, almost colorless liquid with a hint of blue, colorless gas[3]OdorNoneDensityLiquid:[4]
0.9998396 g/mL at 0 °C
0.9970474 g/mL at 25 °C
0.961893 g/mL at 95 °C
Solid:[5]
0.9167 g/ml at 0 °CMelting point0.00 °C (32.00 °F; 273.15 K) [a]Boiling point99.98 °C (211.96 °F; 373.13 K) [6][a]SolubilityPoorly soluble in haloalkanes, aliphaticand aromatic hydrocarbons, ethers.[7]Improved solubility in carboxylates, alcohols, ketones, amines. Miscible with methanol, ethanol, propanol, isopropanol, acetone, glycerol, 1,4-dioxane, tetrahydrofuran, sulfolane, acetaldehyde, dimethylformamide, dimethoxyethane, dimethyl sulfoxide, acetonitrile. Partially miscible with Diethyl ether, Methyl Ethyl Ketone, Dichloromethane, Ethyl Acetate, Bromine.Vapor pressure3.1690 kilopascals or 0.031276 atm[8]Acidity (pKa)13.995[9][10][b]Basicity (pKb)13.995Conjugate acidHydroniumConjugate baseHydroxideThermal conductivity0.6065 W/(m·K)[13]
Refractive index (nD)
1.3330 (20 °C)[14]Viscosity0.890 cP[15]Structure
Crystal structure
Hexagonal
Point group
C2v
Molecular shape
Bent
Dipole moment
1.8546 D[16]Thermochemistry
Heat capacity (C)
75.375 ± 0.05 J/(mol·K)[17]
Std molar
entropy (So298)
69.95 ± 0.03 J/(mol·K)[17]
Std enthalpy of
formation (ΔfHo298)
−285.83 ± 0.04 kJ/mol[7][17]
Gibbs free energy (ΔfG˚)
−237.24 kJ/mol[7]
