Cr + 2HCl → CrCl_{2} + H_{2}

Bạn đang xem: cr + hcl

⬇ Scroll down to tát see reaction info and a step-by-step answer, or balance another equation.

### Word Equation

Chromium + Hydrogen Chloride = Chromous Chloride + Dihydrogen

One mole of

and two moles of

react to tát form one mole of

and one mole of

### Thermodynamics

Thermodynamics of the reaction can be calculated using a lookup table.

#### Is the Reaction Exothermic or Endothermic?

Cr (g) | 1 mol | 397.48 kJ/mol | -397.48 kJ |
---|---|---|---|

HCl (g) | 2 mol | -92.29904 kJ/mol | 184.59808 kJ |

CrCl_{2} (s) | 1 mol | -395.388 kJ/mol | -395.388 kJ |

H_{2} (g) | 1 mol | 0 kJ/mol | 0 kJ |

ΣΔH°_{f}(reactants) | 212.88192 kJ | ||

ΣΔH°_{f}(products) | -395.388 kJ | ||

ΔH°_{rxn} | -608.26992 kJ |

ΣΔH°_{f}(reactants) > ΣΔH°_{f}(products), so sánh Cr + HCl = CrCl2 + H2 is **exothermic** (releases heat).

#### Is the Reaction Exoentropic or Endoentropic?

ΔS = S_{products} - S_{reactants}. If ΔS < 0, it is exoentropic. If ΔS > 0, it is endoentropic.

Cr (g) | 1 mol | 174.22176 J/(mol K) | -174.22176 J/K |
---|---|---|---|

HCl (g) | 2 mol | 186.77376 J/(mol K) | -373.54752 J/K |

CrCl_{2} (s) | 1 mol | 115.31104 J/(mol K) | 115.31104 J/K |

H_{2} (g) | 1 mol | 130.586824 J/(mol K) | 130.586824 J/K |

ΣΔS°(reactants) | 547.76928 J/K | ||

ΣΔS°(products) | 245.897864 J/K | ||

ΔS°_{rxn} | -301.871416 J/K |

ΣΔS°(reactants) > ΣΔS°(products), so sánh Cr + HCl = CrCl2 + H2 is **exoentropic** (decrease in entropy).

#### Is the Reaction Exergonic or Endergonic?

ΔG = G_{products} - G_{reactants}. If ΔG < 0, it is exergonic. If ΔG > 0, it is endergonic.

Cr (g) | 1 mol | 352.58568 kJ/mol | -352.58568 kJ |
---|---|---|---|

HCl (g) | 2 mol | -95.31152 kJ/mol | 190.62304 kJ |

CrCl_{2} (s) | 1 mol | -356.0584 kJ/mol | -356.0584 kJ |

H_{2} (g) | 1 mol | 0 kJ/mol | 0 kJ |

ΣΔG°(reactants) | 161.96264 kJ | ||

ΣΔG°(products) | -356.0584 kJ | ||

ΔG°_{rxn} | -518.02104 kJ |

ΣΔG°(reactants) > ΣΔG°(products), so sánh Cr + HCl = CrCl2 + H2 is **exergonic** (releases energy).

### Reaction Expressions

K_{c} or Q = ( [CrCl_{2}] [H_{2}] ) / ( [Cr] [HCl]^{2} )

(assuming all reactants and products are aqueous. substitutue 1 for any solids/liquids, and Psubstance for gases.)

rate = -(Δ[Cr] / Δt) = -1/2 * (Δ[HCl] / Δt) = (Δ[CrCl_{2}] / Δt) = (Δ[H_{2}] / Δt)

(assuming constant volume in a closed system and no accumulation of intermediates or side products)

## Instructions

To balance a chemical equation, enter an equation of a chemical reaction and press the Balance button. The balanced equation will appear above.

- Use uppercase for the first character in the element and lowercase for the second character. Examples: Fe, Au, Co, Br, C, O, N, F.
- Ionic charges are not yet supported and will be ignored.
- Replace immutable groups in compounds to tát avoid ambiguity. For example, C6H5C2H5 + O2 = C6H5OH + CO2 + H2O will not be balanced, but XC2H5 + O2 = XOH + CO2 + H2O will.
- Compound states [like (s) (aq) or (g)] are not required.
- You can use parenthesis () or brackets [].

## How To Balance Equations

Read our article on how to tát balance chemical equations or ask for help in our chat.

Xem thêm: diên hi công lược

You can also ask for help in our chat or forums.

## Balance Cr + HCl = CrCl2 + H2 Using the Algebraic Method

To balance the equation Cr + HCl = CrCl2 + H2 using the algebraic method step-by-step, you must have experience solving systems of linear equations. The most common methods are substitution/elimination and linear algebra, but any similar method will work.

### Label Each Compound With a Variable

Label each compound (reactant or product) in the equation with a variable to tát represent the unknown coefficients.

a Cr + b HCl = c CrCl

_{2}+ d H_{2}### Create a System of Equations

Create an equation for each element (Cr, H, Cl) where each term represents the number of atoms of the element in each reactant or product.

**Cr**: 1a + 0b = 1c + 0d**H**: 0a + 1b = 0c + 2d**Cl**: 0a + 1b = 2c + 0d### Solve For All Variables

Use substitution, Gaussian elimination, or a calculator to tát solve for each variable.

- 1a - 1c = 0
- 1b - 2d = 0
- 1b - 2c = 0

Use your graphing calculator's rref() function (or an online rref calculator) to tát convert the following matrix into reduced row-echelon-form:

[ 1 0 -1 0 0] [ 0 1 0 -2 0] [ 0 1 -2 0 0]

The resulting matrix can be used to tát determine the coefficients. In the case of a single solution, the last column of the matrix will contain the coefficients.

Simplify the result to tát get the lowest, whole integer values.

- a = 1 (Cr)
- b = 2 (HCl)
- c = 1 (CrCl2)
- d = 1 (H2)

### Substitute Coefficients and Verify Result

Count the number of atoms of each element on each side of the equation and verify that all elements and electrons (if there are charges/ions) are balanced.

Cr + 2 HCl = CrCl

_{2}+ H_{2}Reactants Products Cr 1 1 ✔️ H 2 2 ✔️ Cl 2 2 ✔️ Since there is an equal number of each element in the reactants and products of Cr + 2HCl = CrCl2 + H2, the equation is balanced.

## Balance Cr + HCl = CrCl2 + H2 Using Inspection

The law of conservation of mass says that matter cannot be created or destroyed, which means there must be the same number atoms at the kết thúc of a chemical reaction as at the beginning. To be balanced, every element in Cr + HCl = CrCl2 + H2 must have the same number of atoms on each side of the equation. When using the inspection method (also known as the trial-and-error method), this principle is used to tát balance the one element at a time until both sides are equal and the chemical equation is balanced.

### 1. Count the number of each element on the left and right hand sides

Reactants (Left Hand Side) | Products (Right Hand Side) | ||||||
---|---|---|---|---|---|---|---|

Reactants | Products | ||||||

Cr | HCl | Total | CrCl_{2} | H_{2} | Total | ||

Cr | 1 | 1 | 1 | 1 | ✔️ | ||

H | 1 | 1 | 2 | 2 | ❌ | ||

Cl | 1 | 1 | 2 | 2 | ❌ |

### 2. Multiply coefficients for compounds to tát balance out each element

**H**is not balanced. Add**1**molecule(s) of**HCl**to tát the reactant (left-hand) side to tát balance Hydrogen: Cr + 2HCl = CrCl_{2}+ H_{2}Reactants Products Cr 1 1 ✔️ H 2 2 ✔️ Cl 2 2 ✔️

### 3. Verify that the equation is balanced

Since there are an equal number of atoms of each element on both sides, the equation is balanced.

Cr + 2HCl = CrCl_{2} + H_{2}

Xem thêm: sát thủ john wick

## Bình luận