Litmus paper that is blue will turn/stay _____ in the presence of a strong base.

Litmus paper that is blue will remain blue in the presence of a strong base. This is due to the properties of litmus paper, which is a pH indicator that changes color based on the acidity or basicity of a solution. Blue litmus paper indicates a neutral or basic condition, and when it encounters a strong base, it does not undergo a color change because its inherent alkalinity remains unchanged.

In contrast, substances that are acidic will change blue litmus paper to red, while neutral solutions would leave it unchanged. When a solution’s pH is above 7, such as in the case of strong bases, blue litmus remains blue, reflecting the high pH value typical of basic solutions. The neutrality or basicity is reflected in the stability of the color, which remains consistent as long as the solution remains strongly basic.