The graph below shows the volume and the mass of four different substances at stp.
which of the four substances has the lowest density?
(1) a
(2) b
(3) c
(4) d

Density is defined as the ratio of mass to the volume at standard temperature and pressure. In the graph, substance D will have the lowest density.

Formula of Density:

In the given graph, the substances A, B, C, and D, are measured on the graph.

From the formula, it can be interpreted as density is inversely proportional to volume and directly proportional to the mass. The density will be decreased if volume is decreased, and also, if mass is increased, then density will be increased.

Reasons for incorrect answers:

Therefore, D has the lowest density.

To know more about density, refer to the following link:

link

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.