```
q = mcΔT
```
Where:
- q is the heat absorbed (107 kJ)
- m is the mass of potassium nitrate
- c is the specific heat capacity of potassium nitrate (1.05 J/g°C)
- ΔT is the change in temperature (we can assume it's 1°C)
Substituting the given values into the formula:
```
107 kJ = m * 1.05 J/g°C * 1°C
```
```
m = 107 kJ / (1.05 J/g°C * 1°C)
```
```
m ≈ 102,381 g
```
Therefore, approximately 102,381 grams of potassium nitrate must dissolve in water to absorb 107 kJ of heat.