Excel formula that turns cells into empty cells if the cell next to it is already empty

I need a formula in excel that turns the cells in column D empty if the corresponding cell in column C (i.e. on the same row) is already empty.

To elaborate, this is a sample from my excel sheet:

   C     D
1  0,5   500
2  0.3   400
3        600
4        700
5  3.1   400
6        350
7  1.1   400

I want it to turn into this:

   C     D
1  0,5   500
2  0.3   400
3        
4        
5  3.1   400
6        
7  1.1   400

Is that possible?