There is a web site in the United Kingdom that has the densities of dry materials and it lists the density of baking soda (bicarbonate of soda) as 689 kg/m3. A kilogram is 1000 grams so this is 689000 gm/m3. A metre is 100 centimeters so a cubic meter is 1003 = 1000000 centimeters. Hence the density is
0.689 gm/cm3 = 0.689 gm/ml since a cubic centimeter is one milliliters
1 ml of baking soda weighs 0.689 grams.
I decided to check so I went to my cupboard my found an open box of baking soda, weighed the contents (270 grams) and measured it in a cup measure ( 250 ml). In Canada our cup measures have both Imperial and metric units. This gives
1 ml of baking soda weighs 270/250 = 1.08 grams.
Why the difference? The uk web site has the statement "While the data is useful for the design and selection of bulk materials handling plant, bulk transport and packaging, individual samples will differ. Moisture content will have a marked influence." Moisture content may account for the difference. If you have a kitchen scale I suggest that you try what I did to see what conversion factor you get.