OCR A A Level CHEMISTRY PAPER 1
QUESTIONS| WITH ALREADY SOLVED
CORRECTLY ANSWERS!! | ASSURED
SUCCESS
Test for carbonates - 🧠 ANSWER ✔✔- add dilute HCL
- it makes carbon dioxide
test for carbon dioxide by bubbling it through lime water
Test for ammonium ions - 🧠 ANSWER ✔✔-add sodium hydroxide
-warm the mixture
-hover damp red litmus paper over it , if it turns blue the ions are present
Test for sulphate ionz (SO4 2-) - 🧠 ANSWER ✔✔- add dilute HCL
- then add BaCl2
- BaSO4 is made which is insoluble in water so a white precipitate will be
formed
Test for Halides (Cl-, Br-, I-) - 🧠 ANSWER ✔✔- add nitric acid
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
, - add silver nitrate
- precipitates will be formed
- Cl (white) , Br (cream) , I (yellow)
Why add dilute acids when testing for ions ? - 🧠 ANSWER ✔✔it will get rid
of any lurking anions that may create false positives
Endothermic energy profile diagram - 🧠 ANSWER ✔✔products are higher
than reactants
Exothermic energy profile diagram - 🧠 ANSWER ✔✔reactants are higher
than products
What are standard conditions? - 🧠 ANSWER ✔✔298K and 100kPa
Enthalpy change of reaction - 🧠 ANSWER ✔✔the enthalpy change when
the reaction occurs in molar quantities shown in the chemical equation
under standard conditions
Enthalpy change of formation - 🧠 ANSWER ✔✔the enthalpy change when
1 mole of compound is formed from it's elements in their standard states
under standard conditions
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
QUESTIONS| WITH ALREADY SOLVED
CORRECTLY ANSWERS!! | ASSURED
SUCCESS
Test for carbonates - 🧠 ANSWER ✔✔- add dilute HCL
- it makes carbon dioxide
test for carbon dioxide by bubbling it through lime water
Test for ammonium ions - 🧠 ANSWER ✔✔-add sodium hydroxide
-warm the mixture
-hover damp red litmus paper over it , if it turns blue the ions are present
Test for sulphate ionz (SO4 2-) - 🧠 ANSWER ✔✔- add dilute HCL
- then add BaCl2
- BaSO4 is made which is insoluble in water so a white precipitate will be
formed
Test for Halides (Cl-, Br-, I-) - 🧠 ANSWER ✔✔- add nitric acid
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
, - add silver nitrate
- precipitates will be formed
- Cl (white) , Br (cream) , I (yellow)
Why add dilute acids when testing for ions ? - 🧠 ANSWER ✔✔it will get rid
of any lurking anions that may create false positives
Endothermic energy profile diagram - 🧠 ANSWER ✔✔products are higher
than reactants
Exothermic energy profile diagram - 🧠 ANSWER ✔✔reactants are higher
than products
What are standard conditions? - 🧠 ANSWER ✔✔298K and 100kPa
Enthalpy change of reaction - 🧠 ANSWER ✔✔the enthalpy change when
the reaction occurs in molar quantities shown in the chemical equation
under standard conditions
Enthalpy change of formation - 🧠 ANSWER ✔✔the enthalpy change when
1 mole of compound is formed from it's elements in their standard states
under standard conditions
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
