Can someone please help me im stuck​

The answers to your questions are given below.

Explanation:

1. __H₂ + __O₂ —> __H₂O

The above equation can be balance as follow:

H₂ + O₂ —> H₂O

There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by writing 2 before H₂O as shown below:

H₂ + O₂ —> 2H₂O

There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before H₂ as shown below:

2H₂ + O₂ —> 2H₂O

Now the equation is balanced.

Elements >>> Reactants >>> Products

H >>>>>>>>> 4 >>>>>>>>>>> 4

O >>>>>>>>> 2 >>>>>>>>>>> 2

2. __ P₄ + __O₂ —> __P₂O₃

The above equation can be balance as follow:

P₄ + O₂ —> P₂O₃

There are 4 atoms of P on the left side and 2 atoms on the right side. It can be balance by writing 2 before P₂O₃ as shown below:

P₄ + O₂ —> 2P₂O₃

There are 2 atoms of O on the left side and a total of 6 atoms on the right side. It can be balance by writing 3 before O₂ as shown below:

P₄ + 3O₂ —> 2P₂O₃

Now, the equation is balanced

Elements >>> Reactants >>> Products

P >>>>>>>>> 4 >>>>>>>>>>> 4

O >>>>>>>>> 6 >>>>>>>>>>> 6

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

: )