fix grammar
Concentration 0.1M-1.5M were tested. When number of concentrations increases this enables the datasets with clear trendline and improves validity.
Concentrations ranging from 0.1M to 1.5M were tested. Increasing the number of concentrations allows for datasets with clearer trendlines and improves validity.
To fix the grammar in the sentence, you can make the following changes:
Concentrations ranging from 0.1M to 1.5M were tested. As the number of concentrations increases, this enables the datasets to have a clear trendline and improves their validity.