Yes, if a recipe calls for baking powder, it needs to be used so the batter will rise properly. whether xantuam gum is used or not. Xantham gum is not a leavening agent.
Make a thick paste with baking soda and water, and smooth it over the gum.
No, instead use lime powder
Not always is zanthan gum used in gluten-free baking. It is however desirable because it is a nice thickening agent which helps "bind" the baked product. If not able to use this ingredient, you can substitute it with tapioca flour or potato flour, or even both.
There are so many ads on this page I am getting dizzy, so probably not the best place for baking advice. No, you can't substitute cornstarch every time for xantham gum, certainly not in baking. Yes, they are both gluten free thickening agents (check the source, some types of xantham gum contain wheat, but most specialty grocery stores carry only the GF version like Bob's Red Mill) . However, xantham gum thickens without the use of heat, for example for use as a thickening agent in toothpaste. It is a great stabilizer (as it doesn't separate oils), and is often used in medicines both as a laxative and to stabilize blood sugar. Cornstarch is just cornstarch. It thickens only when heated...yet when heated, cornstarch can actually raise blood glucose levels faster than cane sugar.
You can use any other oil or lard. Cream and other milk products may contain enough fat to have much the same effect as the butter on the texture and taste of your cake. As for fat-free options you could search for and experiment with vegetable gums such as Guar Gum, Pectin, Xantham Gum, etc... that are used in industrial baking as fat substitutes.
If you want it to raise. It takes baking powder regardless of the type of flour. The amount would remain the same.
You can use any or all of these in cake baking. You cannot necessarily use them interchangeably and expect identical results. It is quite usual to use both baking soda and baking powder in the same cake, especially if the recipe calls for an acid ingredient like fruit which will activate the baking soda, but in this case the volume of baking powder has usually been reduced. Baking powder mixes usually contain a small proportion of baking soda anyway. Xanthan gum is most commonly used in making gluten-free products. Gluten is the protein found in flour. Heat, as in baking, toughens protein. Raising agents like baking soda and baking powder give off little bubbles of carbon dioxide during the baking process and these bubbles are held in place by the toughening gluten, rather like little balloons being blown up - this is what causes a cake to rise and hold its shape. Xanthan gum is used in a similar way to add thickness and volume to gluten-free products. If you are wanting to add these raising agents to make a gluten-free product then read the label on the baking powder - it often contains gluten.
i say you use baking soda i use it every time i make cookies
add 2 tea spoons of gum Arabic powder to make a small sponge cake (6 eggs). Add the powder to the dry ingredients. It will help the cake to rise and will add natural soluble fibre to your cake.
you can make a baking soda volcanoes and paint and decorate it for a project
The recipe that I use calls for baking soda.
You cannot use baking powder as a substitute for baking soda