C the answer is cesium, study's show that it has the lowest ionization out of all elements. Hope this helped!
Answer:
=14.8 grams
Explanation:
The remaining amount is normally calculated using the formula:
Remaining mass= 1/2ⁿ × Original mass where n is the number of half-lives.
Therefore, original mass= Remaining mass × 2ⁿ
Remaining mass= 2.2 grams
Number of half lives= 2.75 half lives
Original mass= 2.2g × 2²·⁷⁵
=14.8 grams
Answer:
B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HC
Explanation:
A balanced reaction has the same number of atoms in the both sides of the reaction. In the options:
A. CaCl₂ + H₂CO₃ → 2CaCO₃ + HCI
In this reaction there is 1 Ca in reactants and 2 in products -<em>The reaction is unbalanced-</em>
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<h3>B. CaCl₂ + H₂CO₃ → CaCO₃ + 2HCl
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There is 1 Ca is both sides, 2Cl, 2H, 1C and 3 Oxygens -<em>The reaction is balanced</em>
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C. CaCl₂ + 2H₂CO₃ → CaCO₃ + HCI
There is 1 Ca in both sides but 2Cl in reactants and 1 in Cl -<em>The reaction is unbalanced-</em>
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D. 2CaCl₂ + H₂CO₃ →CaCO₃ + HCI
There are 2 Ca in reactants and 1 in Ca -<em>The reaction is unbalanced-</em>
Here is an acid-base reaction. Hydrochloric acid (HCl) reacts with strontium hydroxide [ Sr(OH)2 ]
Ions H+ and OH- neutralize each other. If the amounts are not equal, one of them will be in excess.
Follow the steps as
1. Find moles of ions: mole= Molarity * Volume (in liter) ; n= M * V OR millimole = Molarity * Volume (in ml) ;
2. Write the equation
3. Find out excess ion
4. Use final volume (V acid + V base ) to calculate concentration of excess ion.
n HCI = 28 ml * 0.10 M = 0.28 mmol, releases 0.28 mmol H+ ions
n Sr(OH)2= 60 ml * 0.10 M= 0.60 mmol, releases 2* 0.60=1.20 mmol OH- ions
since Sr(OH)2⇒ Sr2+ + 2OH-
Neutralization reaction is OH- + H+ ---> H2O. The ratio is 1:1. That means 1 mmol hydroxide ions will neutralize 1 mmol hydrogen ions. Since OH- ions are greater in amount, they will be in excess
n(OH-) - n(H+)= 1.20 - 0.28 = 0.92 mmol OH- ions UNREACTED.
Total volume= V acid + V base= 28 ml + 60 ml = 98 ml
Molarity of OH- ions= mole / Vtotal = 0.92/98= 0.009 M
The answer is 0.009 M.
when the thermal energy is the energy contained within a system that is responsible for its temperature.
and when the thermal energy is can be determined by this formula:
q = M * C *ΔT
when q is the thermal energy
and M is the mass of water = 100 g
and C is the specific heat capacity of water = 4.18 joules/gram.°C
and T is the difference in Temperature = 50 °C
So by substitution:
∴ q = 100 g * 4.18 J/g.°C * 50
= 20900 J = 20.9 KJ