An incomplete chemical equation is given here. which set of numbers, placed in the blanks as the coefficients, will balance the equation shown? __hcl + __na2co3 → __h2co3 + __nacl 1, 2, 1, 2 2, 1, 2, 1 2, 1, 1, 2 2, 2, 1, 1

The answer to your question is the coefficients are 2, 1, 1, 2

Explanation:

Chemical Reaction                            

                              HCl  +   Na₂CO₃   ⇒    H₂CO₃   +   NaCl

                       Reactants            Elements             Products

                               1                         Cl                          1

                               2                         Na                        1

                                1                         C                          1

                                1                         H                         2

                                3                        O                          3

This reaction is unbalanced

                            2 HCl  +   Na₂CO₃   ⇒    H₂CO₃   +   2 NaCl

                       Reactants            Elements             Products

                               1                         Cl                          1

                               2                         Na                        2

                               2                         C                          2

                               2                         H                          2

                               3                        O                          3

Now, the reaction is balanced.

The coefficients are: 2,1,1,2 (Option 3)

Explanation:

Step 1: Unbalanced equation

HCl + Na2CO3 → H2CO3 + NaCl

Step 2 : Balancing the equation

On the right side we have 2x H (in H2CO3), on the left side we have 1x H (in HCl). To balance the amount of H, we have to multiply HCl, on the left side, by 2.

2 HCl  + Na2CO3  →  H2CO3 + NaCl

On the left side we have 2x Na (in Na2CO3), on the right side, we have 1x Na (in NaCl). To balance the amount of Na, we have to multiply NaCl, on the right side, by 2. Now the equation is balanced.

2 HCl  + Na2CO3  →  H2CO3 + 2NaCl

The coefficients are: 2,1,1,2 (Option 3)

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

1.solid

2.carbon dioxide

3.helium