true false questions on nitric acid?

Question

1: Sodium nitrate is generally used because it is inexpensive and sulfuric acid is used because of its high boiling point.
True
False

2: The Ostwald Process involves the oxidation of ammonia.
True
False

3: Pure nitric acid is a blue liquid of low boiling point (86°C).
True
False

4: Nitric acid, when diluted, turns blue litmus paper red.
True
False

5: No nitrates are ever used as fertilizers.
True
False

Answer 1

1) I'd say that's true
2) True
3) I don't know about the blue part but the bp is correct.
4) True
5) False

Answer 2

1. True
2. True
3. False (it's yellow)
4. True
5. False (NH3 is used as a fertilizer)

Answer 3

1: True
2: True
3: False The boiling point is 83C (close enough) but it is water-white. The blue liquid is dinitrogen tetroxide (N2O4), formed by chilling brown nitrogen dioxide (NO2) gas.
4: True
5:False