Answer:
oil floats on water because it is heavier than water
Salt is no longer visible after stirring as salt dissolves in water
by filtration
The reaction of acid, assuming HCl and calcium carbonate always produces a gas. The reaction is as follows:
2 HCl + CaCO3 --> CaCl2 + H2CO3
H2CO3, carbonic acid, is a weak acid that is unstable in water solutions at high concentrations. As such, it decomposes:
H2CO3 --> H2O + CO2
Then,
2 HCl + CaCO3 --> CaCl2 + H2O + CO2
The total ionic equation looks as follows:
2H+(aq) + 2 Cl-(aq) + CaCO3(s) --> Ca+2(aq) + 2 Cl-(aq) + H2O(l) + CO2(g)
Clearly, Cl- is a spectator ion as it is unchanged in the reaction. The net ionic reaction looks as follows:
2 H+(aq) + CaCO3(s) --> Ca+2(aq) + H2O(l) + CO2(g)
The solubility of potassium chloride in at room temperature is approximately 34 g per 100 g of water. Therefore, the maximum amount that could be dissolved would be 34/100 ( 200) = 68 g of KCl. When more than this amount is added, excess potassium would not dissolve forming crystals in the solution.
The pressure of the nitrogen gas produced is determined as 44.77 atm.
<h3>
What is the pressure of the Nitrogen gas?</h3>
The pressure of the nitrogen gas is determined from ideal gas equation, as shown below;
PV = nRT
P = nRT/V
where;
- n is number of moles = 2 moles
- R is ideal gas constant = 0.08205 L.atm/mol.K
- T is temperature = 68⁰C = 68 + 273 = 341 K
- V is volume = 1.25 L
P = (2 x 0.08205 x 341)/(1.25)
P = 44.77 atm.
Learn more about pressure here: brainly.com/question/25736513
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Which of these is an isoelectronic series? 1) na+, k+, rb+, cs+ 2) k+, ca2+, or, s2– 3) na+, mg2+, s2–, cl– 4) li, be, b, c 5) n
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An isoelectronic series is where all of the ions listed have the same number of electrons in their atoms. When an atom has net charge of zero or neutral, it has equal number of protons and electrons. Hence, it means that the atomic number = no. of protons = no. of electrons. If these atoms become ions, they gain a net charge of + or -. Positive ions are cations. This means that they readily GIVE UP electrons, whereas negative ions (anions) readily ACCEPT electrons. So, to know which of these are isoelectronic, let's establish first the number of electron in a neutral atom from the periodic table:
Na=11; K=19; Rb=37; Cs = 55; Ca=20; S=16; Mg=12; Li=3; Be=4; B=5; C=6
A. Na⁺: 11-1 = 10 electrons
K⁺: 19 - 1 = 18 electrons
Rb⁺: 37-1 = 36 electrons
B. K⁺: 19 - 1 = 18 electrons
Ca²⁺: 20 - 2 = 18 electrons
S²⁻: 16 +2 = 18 electrons
C. Na⁺: 11-1 = 10 electrons
Mg²⁺: 12 - 2 = 10 electrons
S²⁻: 16 +2 = 18 electrons
D. Li=3 electrons
Be=4 electrons
B=5 electrons
C=6 electrons
The answer is letter B.
