Will mark brainliest! explain why a mechanical wave does not exist in a vacuum.

answer:

a) pto₂ + 2h₂ ⟶ pt   +   2h₂o

b) 0.021 g

c) 0.010 mol; 0.18 g

step-by-step explanation:

a) balanced equation

we know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

m_r:                 2.016   195.08   18.02

            pto₂ + 2h₂ ⟶ pt   +   2h₂o

m/g:                               1.0

b) mass of h₂

(i) calculate the moles of pt

n = 1.0 g pt   × (1 mol pt /195.08 g pt)

  = 5.13 × 10⁻³ mol pt

(ii) calculate the moles of h₂

the molar ratio is (2 mol h₂/1 mol pt)

n = 5.13 × 10⁻³ mol pt × (2 mol h₂/1 mol pt)

  = 0.0103 mol h₂

(iii) calculate the mass of h₂

m = 0.0103 mol h₂× (2.016 g h₂/1 mol h₂)

m = 0.021 g h₂

you need 0.021 g h₂ to produce 1.00 g pt.

c) moles of water

the molar ratio is (2 mol h₂o/1 mol pt)

  moles of h₂o = 5.13 × 10⁻³ mol pt × (2 mol h₂o/1 mol pt)

                        = 0.010 mol h₂o

mass of water = 0.010 mol h₂o × (18.02 g h₂o/1 mol h₂o)

                        = 0.18 g h₂o

answer:

a. more n₂ and o₂ would formed.

explanation:

n₂ + o₂ ↔ 2 no

answer: option (c) is the correct answer.

explanation:

when a substance changes from solid state to liquid state then this is known as melting of substance. whereas when a substance changes from liquid state to gaseous state then this process is known as boiling of substance.

when solid changes into liquid then there is decrease in force of attraction between the particles. on the other hand, when liquid changes into gaseous form then there are weak force of attraction between the molecules and they tend to move far apart from each other.

thus, we can conclude that bonding forces determines the temperature at which a substance melts and boils.