5G and Blockchain are potentially revolutionizing future technologies. 5G promises high rates and quality of service (QoS) to the users and blockchain guarantees a high level of trust and security among the peers. Applications that would be using 5G have varying needs in terms of speed, bandwidth, latency and various other factors. Augmented reality, self-driving vehicles and other IoT applications tend to use 5G for reliable and fast communication. To work seamlessly and securely in such scenarios a more specialized and efficient approach would be required. In this paper, we have identified the specific areas where blockchain could be utilized to enhance the security and privacy of the 5G services offered to the users. The current challenges faced in deployment and upliftment of 5G and their related solutions based on blockchain are discussed. A model for Multi-Operator Network Slicing in 5G using blockchain is also presented along with 5G blockchain implementation.