KVPY2017Chemistryd and f Block Elements
The fusion of chromite ore ( FeCr ₂ O ₄ ) with Na ₂ CO ₃ in air gives a yellow solution upon addition of water. Subsequent treatment with H ₂ SO ₄ produces an orange solution. The yellow and orange colours, respectively, are due to the formation of
Options
- ANa ₂ CrO ₄ and Na ₂ Cr ₂ O ₇
- BCr ( OH )₃ and Na ₂ Cr ₂ O ₇
- CCr ₂ ( CO ₃ )₃ and Fe ₂ ( SO ₄ )₃
- DCr ( OH )₃ and Na ₂ CrO ₄
Correct answer
A. Na ₂ CrO ₄ and Na ₂ Cr ₂ O ₇
Step-by-step solution
8 Na ₂ CO ₃+4 FeCr ₂ O ₄+7 O ₂ Na ₂ CrO ₄+2 Fe ₂ O ₃+8 O ₂ yellow colour 2 Na ₂ CrO ₄ 2 H ⁺ Na ₂ Cr ₂ O ₇+2 Na ⁺+ H ₂ O yellow orange