diff --git a/src/common/constants.hpp b/src/common/constants.hpp
index a034036..7cb170a 100644
--- a/src/common/constants.hpp
+++ b/src/common/constants.hpp
@@ -19,6 +19,7 @@ namespace constants
 constexpr double R = 8.31446261815324; // J/(mol K)
 constexpr double F = 96485.3321233100184; // C/mol
 constexpr double NA = 6.02214076e23; // 1/mol
+constexpr double waterDensity = 1000.0; // kg/m3
 
 } // namespace constants
 } // namespace hpcReact
diff --git a/src/reactions/exampleSystems/BulkGeneric.hpp b/src/reactions/exampleSystems/BulkGeneric.hpp
index 7f1eedd..926958a 100644
--- a/src/reactions/exampleSystems/BulkGeneric.hpp
+++ b/src/reactions/exampleSystems/BulkGeneric.hpp
@@ -65,7 +65,9 @@ simpleKineticTestRateParams =
   // flag of mobile secondary species
   { 1, 1 },
   // Use the forward and reverse to calculate the kinetic reaction rates
-  0
+  0,
+  // Solvent density
+  1.0
 };
 
 using simpleTestType = reactionsSystems::MixedReactionsParameters< double, int, signed char, 5, 2, 2 >;
@@ -88,7 +90,9 @@ simpleTestRateParams =
   // flag of mobile secondary species
   { 1, 1 },
   // Use the forward and reverse to calculate the kinetic reaction rates
-  0
+  0,
+  // Solvent density
+  1.0
 };
 
 // *****UNCRUSTIFY-ON******
diff --git a/src/reactions/exampleSystems/ChainGeneric.hpp b/src/reactions/exampleSystems/ChainGeneric.hpp
index 196246f..d290472 100644
--- a/src/reactions/exampleSystems/ChainGeneric.hpp
+++ b/src/reactions/exampleSystems/ChainGeneric.hpp
@@ -60,7 +60,8 @@ namespace ChainGeneric
       1  // C3
     },
 
-    0 // Use the forward and reverse to calculate the kinetic reaction rates
+    0, // Use the forward and reverse to calculate the kinetic reaction rates
+    1.0  // Solvent density
   };
 
 // *****UNCRUSTIFY-ON******
diff --git a/src/reactions/exampleSystems/MoMasBenchmark.hpp b/src/reactions/exampleSystems/MoMasBenchmark.hpp
index 3a871b4..83c0c05 100644
--- a/src/reactions/exampleSystems/MoMasBenchmark.hpp
+++ b/src/reactions/exampleSystems/MoMasBenchmark.hpp
@@ -79,7 +79,13 @@ namespace MoMasBenchmark
     1, // C5 = 4X2 + 3X3 + X4
     0, // CS1 = 3X2 + X3 + S
     0  // CS2 = -3X2 + X4 + 2S
-  }
+  },
+
+  // Reaction rates update option
+  1,
+
+  // Solvent density
+  1.0
 };
 
 constexpr mediumCaseType mediumCaseParams =
@@ -154,7 +160,13 @@ constexpr mediumCaseType mediumCaseParams =
     0, // CS1 = 3X2 + X3 + S
     0, // CS2 = -3X2 + X4 + 2S
     1  // Cc = -3X2 + X4 (kinetic)
-  }
+  },
+
+  // Reaction rates update option
+  1,
+
+  // Solvent density
+  1.0
 };
 
 // *****UNCRUSTIFY-ON******
diff --git a/src/reactions/reactionsSystems/Parameters.hpp b/src/reactions/reactionsSystems/Parameters.hpp
index 5933766..35e5d59 100644
--- a/src/reactions/reactionsSystems/Parameters.hpp
+++ b/src/reactions/reactionsSystems/Parameters.hpp
@@ -136,13 +136,15 @@ struct MixedReactionsParameters
                                       CArrayWrapper< RealType, NUM_REACTIONS > const & rateConstantForward,
                                       CArrayWrapper< RealType, NUM_REACTIONS > const & rateConstantReverse,
                                       CArrayWrapper< IntType, NUM_REACTIONS > mobileSecondarySpeciesFlag,
-                                      IntType const reactionRatesUpdateOption = 1 ):
+                                      IntType const reactionRatesUpdateOption = 1,
+                                      RealType const solventDensity = constants::waterDensity ):
     m_stoichiometricMatrix( stoichiometricMatrix ),
     m_equilibriumConstant( equilibriumConstant ),
     m_rateConstantForward( rateConstantForward ),
     m_rateConstantReverse( rateConstantReverse ),
     m_mobileSecondarySpeciesFlag( mobileSecondarySpeciesFlag ),
-    m_reactionRatesUpdateOption( reactionRatesUpdateOption )
+    m_reactionRatesUpdateOption( reactionRatesUpdateOption ),
+    m_solventDensity( solventDensity )
   {}
 
   HPCREACT_HOST_DEVICE static constexpr IndexType numReactions() { return NUM_REACTIONS; }
@@ -239,6 +241,8 @@ struct MixedReactionsParameters
     }
   }
 
+  HPCREACT_HOST_DEVICE constexpr RealType getSolventDensity() const { return m_solventDensity; }
+
   HPCREACT_HOST_DEVICE IndexType stoichiometricMatrix( IndexType const r, int const i ) const { return m_stoichiometricMatrix[r][i]; }
   HPCREACT_HOST_DEVICE RealType equilibriumConstant( IndexType const r ) const { return m_equilibriumConstant[r]; }
   HPCREACT_HOST_DEVICE RealType rateConstantForward( IndexType const r ) const { return m_rateConstantForward[r]; }
@@ -251,6 +255,7 @@ struct MixedReactionsParameters
   CArrayWrapper< IntType, NUM_REACTIONS > m_mobileSecondarySpeciesFlag;
 
   IntType m_reactionRatesUpdateOption; // 0: forward and reverse rate. 1: quotient form.
+  RealType m_solventDensity; // Unit should be kg/m3
 };