If a plant with purple petals (pp) is crossed with a plant with white petals (pp), what is the phenotype for the f1 generation?

The correct answer is-

The phenotype ( physical appearance) for the F1 generation is Purple petals.

As per the information in the question, the genotypes of parent plants are-

PP ( showing purple petals) and pp ( showing white petals).

This indicates that purple petals is a dominant trait ( expressed by capital letter allele).

White petal is a recessive trait (expressed by small letter allele)

A dominant trait masks the expression of recessive trait. Purple petal can have two genotypes that is Pp ( heterozygous dominant) and PP ( homozygous dominant) whereas white petal will exhibit only in the genotype pp ( homozygous recessive).

When these two parents are crossed, they will produce all plants with purple petal ( genotype Pp) in F1 generation.  

d. sodium chloride ions.