Answer: It just haven’t been discovered yet
Explanation:
Because the periodic table was discovered long ago some elements haven’t been discovered thats why it maybe has 3 columns
An exothermic reaction releases 86.5 kJ. How many kilocalories of
energy are released?
U ever get an answer
What is the mass of 0.5 moles of hydrogen gas
Answer:
1G
Explanation:
Choose the names of the substances for reactants of the equation
2H2 + O2—— 2H2O
The names of the substances for the reactants in the chemical equation 2H₂ + O₂ → 2H₂O are; Hydrogen gas (H₂) and Oxygen gas (O₂). Option A and C is correct.
Hydrogen gas (H₂) - This is the molecular form of hydrogen, consisting of two hydrogen atoms bonded together.
Oxygen gas (O₂) - This is the molecular form of oxygen, consisting of two oxygen atoms bonded together.
In a chemical equation, the reactants are the substances that undergo a chemical reaction to form new products. In this case, the reactants are hydrogen gas (H₂) and oxygen gas (O₂). The arrow (→) in the equation represents the direction of the reaction, indicating that hydrogen gas and oxygen gas react to form water (H₂O).
The coefficient 2 in front of H₂ and H₂O indicates that two molecules of hydrogen gas react with one molecule of oxygen gas to produce two molecules of water. The balanced chemical equation shows the stoichiometry of the reaction, indicating the number of molecules of each reactant and product involved in the reaction.
Hence, A. C. is the correct option.
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--The given question is incomplete, the complete question is
"Choose the names of the substances for reactants of the equation
2H₂ + O₂ → 2H₂O Options; A) Hydrogen B) Water C) Oxygen."--
The city council of a small town wanted to add fluoride to their water so that all the residents would have healthier teeth. The mayor had read that ionic compounds must be used to get the fluoride into water. He looked up fluorine-containing compounds and came up with the following list.
NaF NF3 SiF4 CaF2 NH4F
Using academic vocabulary in paragraph form, discuss the following:
Explain which compound(s) could produce fluoride ions in the water. In your response, be sure to include:
° which of the listed compounds are ionic and which are covalent.
° how ionic and covalent compounds are different.
° why only ionic compounds would produce fluoride in water.
Answer:NaF is ionic. NF3 is covalent. SiF4 is ionic. CaF2 is Ionic and NH4F is also ionic. Ionic compounds transfer electrons whereas covalent compounds share electrons hence the word "co". Also, ionic compounds are formed with metal and nonmetal. Where a covalent is with 2 nonmetals. Only ionic compounds would produce fluoride in water because ionic compounds can dissolve in water and covalent compounds cant.
The compounds that can be used for the release of fluorine in water are NaF, [tex]\rm SiF_4[/tex], [tex]\rm CaF_2[/tex], and [tex]\rm NH_4F[/tex].
The ionic compounds are formed by the transfer of electrons between the atoms of the compounds. The ionic bonds are weaker and are easy to dissociate in the aqueous solution.
The covalent compounds are formed by the sharing of electrons between the atoms. Since there is sharing, there has been a strong bond, that has been hard to dissociate.
The Mayor has to release Fluoride in the water, thus ionic compounds are preferred that have the easy release of fluorine.
From the given compounds:
NaF = Ionic compound[tex]\rm NF_3[/tex] = Covalent compound[tex]\rm SiF_4[/tex] = Ionic compound[tex]\rm CaF_2[/tex] = Ionic compound[tex]\rm NH_4F[/tex] = Ionic compoundThus the compounds that can be used for the release of fluorine in water are NaF, [tex]\rm SiF_4[/tex], [tex]\rm CaF_2[/tex], and [tex]\rm NH_4F[/tex].
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Lead (II) nitrate is reacted with sodium chloride to form a precipitate. What volume (in mL) of 0.666 M lead (II) nitrate is required to react with 517 mL of 2.27 M sodium chloride solution
Answer:
Explanation:
lead 3 is correct!!!!!
how do you separate the following mixture? Name only the process involved .
1.Sand and salt
Answer:
Just dissolve in water , you can separate
Explanation:
because salt dissolves in water but sand doesn't
Explanation:
sedinentation and decantation
A vapor volume of 1.17 L forms when a sample of liquid acetonitrile, CH3CN, absorbs 1.00 kJ of heat at its normal boiling point (81.6 °C and 1 atm). What is Hvap in kilojoules per mole of CH3CN?
The heat of vaporization of CH3CN is obtained from the question as 25 KJ/mol.
We can obtain the number of moles from;
PV = nRT
P = 1 atm
V = 1.17 L
n = ?
R = 0.082 atm LK-1mol-1
T = 81.6 °C + 273 = 354.6 K
n = PV/RT
Substituting values;
n = 1 atm × 1.17 L/0.082 atm LK-1mol-1 × 354.6 K
n = 0.04 moles
Using; q = n·ΔHv
q = Heat absorbed
n = number of moles
Hv = Heat of vaporization
ΔHv = q/n
ΔHv = 1.00 × 10^3/0.04
ΔHv = 25 KJ/mol
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Your private gas collection consists of the four following gases, with each gas in a separate container, and exactly 1.0 g of each gas: CO2(g). Ne (g), Cl2
(g), and H2S (g). Which of your prized gases occupies the smallest volume at standard temperature and pressure (STP)?
H2S (g)
CO2 (g)
Cl2 (g)
Ne (g)
Answer:Cl2
Explanation:each gas is 1 gm and has the same P andT. The gas with the highest molar mass will have the lowest volume with least moles. Cl2 wins the prize
