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usmsankhan
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"Suggest 2 reasons why the reaction of calcium with sulpuric is faster at first than magnesium with Hcl
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Libaan
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In group 2 of the periodic table, the reactivity increases as you go down and since calcium is below magnesium, its going to react faster. This is due to the increasing atomic radius and shielding effect. Also they lose electrons, and form cations, so the easier it is to lose the electrons, the more reactive it becomes.
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derpz
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(Original post by usmsankhan)
"Suggest 2 reasons why the reaction of calcium with sulpuric is faster at first than magnesium with Hcl

Both Calcium and Magnesium are in Group 2, so you should be thinking about their reactivity. You know that as you go down the group, reactivity increases because first ionisation energy increases so they react more readily (due to higher PEL and increased shielding).

Im unsure what the second reason could be, maybe something to do with the fact that most o the reagants are used up faster?
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usmsankhan
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Thanks guys but does anyone know what the second reason maybe ?
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Pigster
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Assuming the acids are the same conc, they will have different pHs, which is your second reason.

Problem is, CaSO4 isn't all that soluble, so after a short while, the Ca will be covered with ppt, slowing/stopping the reaction.
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K3001N
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OCR H032

Hi Guys, I need some help on this

  1. A reaction of calcium with sulphuric acid was faster than the reaction of magnesium with HCL. However the reaction of calcium with sulphuric acid soon stopped even though some calcium remained. A white solid formed. Give two reasons why the reaction was faster at first with calcium and sulphuric acid than with magnesium and hydrochloric acid

2) Identify the white solid and write and equation for the formation in this reaction. Explain why the reaction of calcium and sulphuric acid stopped even though some calcium remained White solid___________________________ ________________________________ _________
Equation________________________ ________________________________ ______________
Explanation_____________________ ________________________________ ________________

________________________________ ________________________________ ______________

________________________________ ________________________________ ______________
3) A Grignard reagent is a compound in which magnesium is bonded to an alkyl group (R) and a halogen (X). It can be represented by the formula RMgX. A Grignard reagent is formed by the reaction of magnesium metal with haloalkane using dry ethoxyethane as a solvent. Ethoxyethane has a boiling point of 35 centigrade, forms a dense vapour and is highly flammable. Give one reason why a hot water bath is used rather than direct heating with a bunsen burner when preparing the Grignard reagent
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usmsankhan
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(Original post by Pigster)
Assuming the acids are the same conc, they will have different pHs, which is your second reason.

Problem is, CaSO4 isn't all that soluble, so after a short while, the Ca will be covered with ppt, slowing/stopping the reaction.
Thanks mate , so the second reason is that the calcium is faster as it forms a different ph?
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usmsankhan
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(Original post by K3001N)
OCR H032

Hi Guys, I need some help on this
  1. A reaction of calcium with sulphuric acid was faster than the reaction of magnesium with HCL. However the reaction of calcium with sulphuric acid soon stopped even though some calcium remained. A white solid formed. Give two reasons why the reaction was faster at first with calcium and sulphuric acid than with magnesium and hydrochloric acid
2) Identify the white solid and write and equation for the formation in this reaction. Explain why the reaction of calcium and sulphuric acid stopped even though some calcium remained White solid___________________________ ________________________________ _________
Equation________________________ ________________________________ ______________
Explanation_____________________ ________________________________ ________________

________________________________ ________________________________ ______________

________________________________ ________________________________ ______________
3) A Grignard reagent is a compound in which magnesium is bonded to an alkyl group (R) and a halogen (X). It can be represented by the formula RMgX. A Grignard reagent is formed by the reaction of magnesium metal with haloalkane using dry ethoxyethane as a solvent. Ethoxyethane has a boiling point of 35 centigrade, forms a dense vapour and is highly flammable. Give one reason why a hot water bath is used rather than direct heating with a bunsen burner when preparing the Grignard reagent
for question 3 I would say that it's less dangerous as the solvents flammable remember
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usmsankhan
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(Original post by K3001N)
OCR H032

Hi Guys, I need some help on this
  1. A reaction of calcium with sulphuric acid was faster than the reaction of magnesium with HCL. However the reaction of calcium with sulphuric acid soon stopped even though some calcium remained. A white solid formed. Give two reasons why the reaction was faster at first with calcium and sulphuric acid than with magnesium and hydrochloric acid
2) Identify the white solid and write and equation for the formation in this reaction. Explain why the reaction of calcium and sulphuric acid stopped even though some calcium remained White solid___________________________ ________________________________ _________
Equation________________________ ________________________________ ______________
Explanation_____________________ ________________________________ ________________

________________________________ ________________________________ ______________

________________________________ ________________________________ ______________
3) A Grignard reagent is a compound in which magnesium is bonded to an alkyl group (R) and a halogen (X). It can be represented by the formula RMgX. A Grignard reagent is formed by the reaction of magnesium metal with haloalkane using dry ethoxyethane as a solvent. Ethoxyethane has a boiling point of 35 centigrade, forms a dense vapour and is highly flammable. Give one reason why a hot water bath is used rather than direct heating with a bunsen burner when preparing the Grignard reagent
Grignard reagent reacts with water . Suggest one reason why ethoxyethane protects the Grignard reagent reacting with water vapour in air ??
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